Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.

The International Large Detector: Letter of Intent

The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a push-pull scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account.

Tests of a Roman Pot Prototype for the TOTEM Experiment

The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC. TOTEM Roman Pots contain stacks of 10 silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10 sigma + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place first in a fixed-target muon beam at CERN's SPS, and then in the proton beam-line of the SPS accelerator ring. We present the test beam results demonstrating the successful functionality of the system despite slight technical shortcomings to be improved in the near future.

Avoimesti sitoutuneena : Lähetystyö kristillisessä kasvatuksessa ja vapaaehtoistyössä

In this study the junction of Christian mission, Christian education and voluntary work are examined in the Christian student voluntary association Opiskelijain Lähetysliitto (OL), which is the Finnish successor to the Student Volunteer Movement. The main subjects are the structure and content of the mission education as one aspect of Lutheran education and the reasons for expressing the mission interest through voluntary work. The research questions are as follows: What kind of organization has the OL been? What has mission education been like in the OL? Why have the former chairpersons participated in the OL? How have purposiveness and intentionality arisen among the former chairpersons? The study is empirical despite having a historical and retrospective view, since the OL is explored during the period 1972 2000. The data consists of the OL s annual reports, membership applications (N=629) and interviews of all 25 former chairmen. Data is analysed by qualitative and quantitative content analysis in a partly inductive and partly deductive manner. The pedagogical framework arises from situational learning theory (Lave - Wenger 1991), which was complemented with the criteria for meaningful learning (Jonassen 1995), the octagon model of volunteer motivation (Yeung 2004) and the definitions of intentionality and purposiveness in the theory of teachers pedagogical thinking (Kansanen et al. 2000). The analysis of the archive data showed that the activities of the OL are reminiscent of those of the missions of the Finnish Evangelical Lutheran Church congregations. The biggest difference was that all OL participants were young adults, the age group that is the greatest challenge to the Church. The OL is therefore an interesting context in which to explore mission education and mission interest. The key result of the study was the forming of a model of mission educa-tion. The model has three educational components: values, goals and methods. The gist of the model is formed by the goals. The main goal is the arousing and strengthening of mission interest which has emotional, cognitive and practical aspects. The subgoals create the horizontal vertical and inward outward dimensions of the model, which are the metalevels of mission education. The subgoals reveal that societal and religious education may embody a missionary dimension when they are understood as missionary training. Further, a distinction between mission education and missionary training was observed. The former emphasizes the main goal of the model and the latter underlines the subgoals. Based on the vertical dimension of the model the study suggests that the definition of religious competence needs to be complemented with missional competence. Reasons for participating in the OL were found to be diverse as noted in other studies on volunteering and motivating factors, and were typical to young people such as the importance of social relations. The study created new motivational themes that occurred in the middle of the continuity newness and the distance proximity dimensions, which were not found in Yeung s research. Mission interest as voluntary work appeared as oriented towards one s own spirituality or towards the social community. On the other hand, mission interest was manifested as intentional education in order to either improve the community or to promote the Christian mission. In the latter case the mission was seen as a purpose in life and as a future profession. Keywords: mission, Christian education, voluntary work, mission education, mission interest, stu-dent movement

Position-sensitive silicon strip detector characterization using particle beams

Silicon strip detectors are fast, cost-effective and have an excellent spatial resolution. They are widely used in many high-energy physics experiments. Modern high energy physics experiments impose harsh operation conditions on the detectors, e.g., of LHC experiments. The high radiation doses cause the detectors to eventually fail as a result of excessive radiation damage. This has led to a need to study radiation tolerance using various techniques. At the same time, a need to operate sensors approaching the end their lifetimes has arisen. The goal of this work is to demonstrate that novel detectors can survive the environment that is foreseen for future high-energy physics experiments. To reach this goal, measurement apparatuses are built. The devices are then used to measure the properties of irradiated detectors. The measurement data are analyzed, and conclusions are drawn. Three measurement apparatuses built as a part of this work are described: two telescopes measuring the tracks of the beam of a particle accelerator and one telescope measuring the tracks of cosmic particles. The telescopes comprise layers of reference detectors providing the reference track, slots for the devices under test, the supporting mechanics, electronics, software, and the trigger system. All three devices work. The differences between these devices are discussed. The reconstruction of the reference tracks and analysis of the device under test are presented. Traditionally, silicon detectors have produced a very clear response to the particles being measured. In the case of detectors nearing the end of their lifefimes, this is no longer true. A new method benefitting from the reference tracks to form clusters is presented. The method provides less biased results compared to the traditional analysis, especially when studying the response of heavily irradiated detectors. Means to avoid false results in demonstrating the particle-finding capabilities of a detector are also discussed. The devices and analysis methods are primarily used to study strip detectors made of Magnetic Czochralski silicon. The detectors studied were irradiated to various fluences prior to measurement. The results show that Magnetic Czochralski silicon has a good radiation tolerance and is suitable for future high-energy physics experiments.

Functions of human papillomavirus E5 oncogene in epithelial cells and in the onset of cervical cancer

Human papillomaviruses (HPVs) are the causal agents of cervical cancer, which is the second most common cancer among women worldwide. Cellular transformation and carcinogenesis depend on the activities of viral E5, E6 and E7 proteins. Alterations in cell-cell contacts and in communication between epithelial cells take place during cervical carcinogenesis, leading to changes in cell morphology, increased cell motility and finally invasion. The aim of this thesis was to study genome-wide effects of the HPV type 16 (HPV-16) E5 protein on the expression of host cell messenger RNAs (mRNAs) and microRNAs by applying microarray technology. The results showed that the HPV-16 E5 protein alters several cellular pathways involved in cellular adhesion, motility and proliferation as well as in the extracellular matrix. The E5 protein was observed to enhance wound healing of epithelial cell monolayers by increasing cell motility in vivo. HPV-16 E5-induced alterations in the expression of cellular microRNAs and their target genes seem to favour increased proliferation and tumorigenesis. E5 was also shown to affect the expression of adherens junction proteins in HaCaT epithelial keratinocytes. In addition, a study of a membrane cytoskeletal cross-linker protein, ezrin, revealed that when activated, it localizes to adherens junctions. The results suggest that ezrin distribution to forming adherens junctions is due to Rac1 activity in epithelial cells. These studies reveal for the first time the holistic effects of HPV-16 E5 protein in promoting precancerous events in epithelial cells. The results contribute to identifyinging novel markers for cervical precancerous stages and to predicting disease behaviour.