Wire Scanner Motion Control Card

Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The FPGAs will act as the control unit of the system. As the LHC has two separate vacuum chambers for the two counter rotating proton-beams, a wire scanner is needed for both the horizontal and vertical beam profile measurement. One motion control card is expected to control two wire scanners. The position of the wires must be acquired within a certain accuracy to meet the specification set for the LHC. In order to obtain the correct beam profile, the position acquisition must be well synchronized with the acquisition of the beam density. The values have to be stored in a memory, which is readable through the VME64x-bus

Music journalists, music press officers and the consumer music press in the UK

This thesis presents a professional/organisational analysis of popular music journalism in the UK. It considers the conditions under which consumer music magazines are produced (at the level of both the newsroom and the publishing organisation) and how music journalists deal with their main point of informational contact, the press officer. Drawing on original interview and participant observation research, the thesis considers: the economic and bureaucratic forces within magazine publishing organisations; how titles are positioned both individually and collectively as part of portfolio of niched titles; how market forces condition how and why titles are launched, redesigned and folded; and, ultimately, how all these factors impact upon and shape the socio-professional and cultural conditions under which editors and their staff work. The thesis then considers the music press officer (both in-house and independent and their office/departmental hierarchies) in terms of how they exist and operate at the meeting point of three distinct groups: the artists they are employed to represent; the artists' record companies; and the press (and their attempts to reconcile these often divergent needs). Having considered the music press and music journalists in isolation (in terms of power structures as well as their collective and individual goals) and press officers in isolation (in terms of their position within wider music industry promotional strategies and how they build, develop and revise a roster of artists) the thesis then moves on to analyse how these two distinct professional groups (journalists/editors and press officers) work together, how they professionally and organisationally define their goals and objectives and the steps they take to meet these goals and objectives, negotiating quantitatively and qualitatively the coverage of artists. A complex relationship of conditional power and mutual dependency links these two sets of professionals in both their formal activities and their socio-cultural activities. Breaking from previous studies that have described a uni-directional flow of power and influence of press officers over the press, the thesis argues that the relationships that tie these groups together (in terms of gatekeeping within the hierarchy of the newsroom and a tilting balance of power) are much more complex that has previously been assumed

Effects of Finite and Discrete Sampling and Blur on Microrheology Experiments

The frequency-dependent viscous and elastic properties of fluids can be determined from measurements of the thermal fluctuations of a micron-sized particle trapped by optical tweezers. Finite bandwidth and other instrument limitations lead to systematic errors in measurement of the fluctuations. In this work, we numerically represented power spectra of bead position measurements as if collected by two different measurement devices: a quadrant photodiode, which measures the deflection of the trapping laser; and a high-speed camera, which images the trapped bead directly. We explored the effects of aliasing, camera blur, sampling frequency, and measurement time. By comparing the power spectrum, complex response function, and the complex shear modulus with the ideal values, we found that the viscous and elastic properties inferred from the data are affected by the instrument limitations of each device. We discuss how these systematic effects might affect experimental results from microrheology measurements and suggest approaches to reduce discrepancies

Returns, Volatility and Liquidity on the ASX: Undisclosed vs. Disclosed Limit Orders

This paper investigates the information content of the two types of limit orders on the Australian Stock Exchange ASX: undisclosed orders (ULOs) and limit orders. Given the large order quantity contained in ULOs, we attempt to examine the impact of ULO submissions, cancellations and executions on price changes and volatility over differing intervals within a day. Motivation is generated by the ASX decision to abolish the use of ULOs in favour of iceberg orders. Intraday analysis shows that the impact of both ULO and disclosed order submissions are no longer than one day. ULO buying/selling order submissions at the best bid/ask price increase/decrease returns and price volatility significantly more than disclosed orders. The cancellations of ULOs cause significantly larger price volatility than disclosed limit order cancellations. Compared with disclosed limit order submissions, there is an increase in liquidity from the significantly reduced spread upon DLO submissions.Intraday effects, Return volatility, Undisclosed limit orders

Evolutionary History, Immigration History, and the Extent of Diversification in Community Assembly

During community assembly, species may accumulate not only by immigration, but also by in situ diversification. Diversification has intrigued biologists because its extent varies even among closely related lineages under similar ecological conditions. Recent research has suggested that some of this puzzling variation may be caused by stochastic differences in the history of immigration (relative timing and order of immigration by founding populations), indicating that immigration and diversification may affect community assembly interactively. However, the conditions under which immigration history affects diversification remain unclear. Here we propose the hypothesis that whether or not immigration history influences the extent of diversification depends on the founding populations’ prior evolutionary history, using evidence from a bacterial experiment. To create genotypes with different evolutionary histories, replicate populations of Pseudomonas fluorescens were allowed to adapt to a novel environment for a short or long period of time (approximately 10 or 100 bacterial generations) with or without exploiters (viral parasites). Each evolved genotype was then introduced to a new habitat either before or after a standard competitor genotype. Most genotypes diversified to a greater extent when introduced before, rather than after, the competitor. However, introduction order did not affect the extent of diversification when the evolved genotype had previously adapted to the environment for a long period of time without exploiters. Diversification of these populations was low regardless of introduction order. These results suggest that the importance of immigration history in diversification can be predicted by the immigrants’ evolutionary past. The hypothesis proposed here may be generally applicable in both micro- and macro-organisms

Ethical difficulties in clinical practice : experiences of European doctors

Background: Ethics support services are growing in Europe to help doctors in dealing with ethical difficulties. Currently, insufficient attention has been focused on the experiences of doctors who have faced ethical difficulties in these countries to provide an evidence base for the development of these services. Methods: A survey instrument was adapted to explore the types of ethical dilemma faced by European doctors, how they ranked the difficulty of these dilemmas, their satisfaction with the resolution of a recent ethically difficult case and the types of help they would consider useful. The questionnaire was translated and given to general internists in Norway, Switzerland, Italy and the UK. Results: Survey respondents (n = 656, response rate 43%) ranged in age from 28 to 82 years, and averaged 25 years in practice. Only a minority (17.6%) reported having access to ethics consultation in individual cases. The ethical difficulties most often reported as being encountered were uncertain or impaired decisionmaking capacity (94.8%), disagreement among caregivers (81.2%) and limitation of treatment at the end of life (79.3%). The frequency of most ethical difficulties varied among countries, as did the type of issue considered most difficult. The types of help most often identified as potentially useful were professional reassurance about the decision being correct (47.5%), someone capable of providing specific advice (41.1%), help in weighing outcomes (36%) and clarification of the issues (35.9%). Few of the types of help expected to be useful varied among countries. Conclusion: Cultural differences may indeed influence how doctors perceive ethical difficulties. The type of help needed, however, did not vary markedly. The general structure of ethics support services would not have to be radically altered to suit cultural variations among the surveyed countries