Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector

For the HERA upgrade, the ZEUS experiment has designed and installed a high precision Micro Vertex Detector (MVD) using single sided micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 microns, with five intermediate strips (20 micron strip pitch). An extensive test program has been carried out at the DESY-II testbeam facility. In this paper we describe the setup developed to test the ZEUS MVD sensors and the results obtained on both irradiated and non-irradiated single sided micro-strip detectors with rectangular and trapezoidal geometries. The performances of the sensors coupled to the readout electronics (HELIX chip, version 2.2) have been studied in detail, achieving a good description by a Monte Carlo simulation. Measurements of the position resolution as a function of the angle of incidence are presented, focusing in particular on the comparison between standard and newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM

Temperatuurgevoeligheid van Guzmania en Vriesea na de bloei-inductie

In de winter van 2003-2004 is – onder begeleiding van enthousiaste begeleidingscommissie onderzoek (BCO) van de landelijke LTO Bromeliacommissie - een teeltproef uitgevoerd waarbij de invloed van de ruimtetemperatuur (16, 20, of 24°C) in verschillende perioden (1e, 2e of 3e maand) na de bloeibehandeling op het bloeiresultaat en de teeltduur van Guzmania en Vriesea onderzocht is. Doel hierbij was de mogelijkheden tot energiebesparing gedurende een koude periode te onderzoeken, bij voorbeeld door een lagere temperatuur later in de teelt door een hogere teelttemperatuur te compenseren

Diamond detectors for future particle physics experiments

Diamond has recently been shown to be a viable material for detectors in experiments at the next generation of particle accelerators. This contribution surveys the properties of diamond which give it advantages, the results achieved to date, the remaining unresolved issues, and the possible applications for diamond detectors in the future

Targetclone: A multi-sample approach for reconstructing subclonal evolution of tumors

Most tumors are composed of a heterogeneous population of subclones. A more detailed insight into the subclonal evolution of these tumors can be helpful to study progression and treatment response. Problematically, tumor samples are typically very heterogeneous, making deconvolving individual tumor subclones a major challenge. To overcome this limitation, reducing heterogeneity, such as by means of microdissections, coupled with targeted sequencing, is a viable approach. However, computational methods that enable reconstruction of the evolutionary relationships require unbiased read depth measurements, which are commonly challenging to obtain in this setting. We introduce TargetClone, a novel method to reconstruct the subclonal evolution tree of tumors from single-nucleotide polymorphism allele frequency and somatic single-nucleotide variant measurements. Furthermore, our method infers copy numbers, alleles and the fraction of the tumor component in each sample. TargetClone was specifically designed for targeted sequencing data obtained from microdissected samples. We demonstrate that our method obtains low error rates on simulated data. Additionally, we show that our method is able to reconstruct expected trees in a testicular germ cell cancer and ovarian cancer dataset. The TargetClone package including tree visualization is written in Python and is publicly available at https://github.com/UMCUGenetics/targetclone