2,424 research outputs found
Requirements and trends in the control of accelerators
The primary requirement for any accelerator control sys-tem must be to enable the operator to deliver the accel-erated particles to the users in an effective and efficient way. This breaks down into separate requirements for the equipment, the control system hardware and for the soft-ware. The requirements and the extent to which control systems satisfy them are examined. Whilst there is no single direction in which control systems are converging, there are a number of trends reflected in the main thrust of new developments. These trends and their consequences are discussed.
The Dismantling Project for the Large Electron Positron (LEP) Collider
The LEP accelerator was installed in a circular tunnel 27 km in length with nine access points distributed around the circumference in the countryside and villages which surround CERN's sites. The dismantling project involved the removal in less than 15 months of around 29000 tonnes of equipment from the accelerator itself and a further 10000 tonnes from the four experiments - all of which were located at an average depth of 100 m below ground level. There was no contamination risk in the project and less than 3% of the materials removed were classified as radioactive. However, the materials which were classified as radioactive have to be temporarily stored and they consume considerable resources. The major difficulties for the project were in the establishment of the theoretical radiological zoning, implementation of the traceability systems and making appropriate radiation measurements to confirm the zoning. The absence of detailed guidelines from the French authorities, having no threshold levels for release of radioactive materials and being the first dismantling project of a large accelerator made the task more difficult and more expensive. Further difficulties remain because materials classified as having very weak radioactivity (trĂšs faiblement actif -TFA) by the zoning study which have no induced activity have to be treated in the same way as radioactive waste. This paper describes the organisation of the project and its execution and examines some of the problems which arise from the INB system; the radiation protection aspects of the project are discussed in the paper entitled "DĂ©classement du grand collisionneur d'electrons/positrons (LEP) du CERN", also presented at this conference
Panel discussion
"The Importance of Being Predictable" by John B. Taylor -- "Monetary Policy Under Uncertainty" by Ben S. Bernanke -- "The Importance of Being Predictable" by William PooleMonetary policy
Panel discussion monetary policy modeling: where are we and where should we be going?
Monetary policy ; Inflation (Finance) ; Econometric models
Sedimentology, neotectonics and geomorphology related to tectonic uplift and sea-level change quaternary of Cyprus
Sleepless latency of human cytomegalovirus.
As with all human herpesviruses, human cytomegalovirus (HCMV) persists for the lifetime of the host by establishing a latent infection, which is broken by periodic reactivation events. One site of HCMV latency is in the progenitor cells of the myeloid lineage such as CD34+ cells and their CD14+ derivatives. The development of experimental techniques to isolate and culture these primary cells in vitro is enabling detailed analysis of the events that occur during virus latency and reactivation. Ex vivo differentiation of latently infected primary myeloid cells to dendritic cells and macrophages results in the reactivation of latent virus and provides model systems in which to analyse the viral and cellular functions involved in latent carriage and reactivation. Such analyses have shown that, in contrast to primary lytic infection or reactivation which is characterised by a regulated cascade of expression of all viral genes, latent infection is associated with a much more restricted viral transcription programme with expression of only a small number of viral genes. Additionally, concomitant changes in the expression of cellular miRNAs and cellular proteins occur, and this includes changes in the expression of a number of secreted cellular proteins and intracellular anti-apoptotic proteins, which all have profound effects on the latently infected cells. In this review, we concentrate on the effects of one of the latency-associated viral proteins, LAcmvIL-10, and describe how it causes a decrease in the cellular miRNA, hsa-miR-92a, and a concomitant upregulation of the GATA2 myeloid transcription factor, which, in turn, drives the expression of cellular IL-10. Taken together, we argue that HCMV latency, rather than a period of viral quiescence, is associated with the virally driven manipulation of host cell functions, perhaps every bit as complex as lytic infection. A full understanding of these changes in cellular and viral gene expression during latent infection could have far-reaching implications for therapeutic intervention.We thank the MRC for funding, Grant Number G0701279. This research was supported by the Cambridge NIHR BRC cell phenotyping hub.This is the final published version. It first appeared at http://link.springer.com/article/10.1007%2Fs00430-015-0401-6
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