The New Control and Interlock System for the SPS Main Power Converters

The Control and Interlock System (CIS) of the SPS main power converters was designed in the mid-70s and became increasingly difficult to maintain. A new system based on Programmable Logic Controllers has been developed by an external contractor in close collaboration with CERN. The system is now operational and fully integrated in the SPS/LEP control infrastructure. The CIS is the first major contracted industrial solution used to control accelerator equipment directly involved in the production of particle beams at CERN. This paper gives an overview of the SPS main power converter installation and describes both the contractual and technical solution adopted for the CIS. It first explains how the system was specified and how the contractual relationship was defined to respect CERNs purchasing rules and the operational requirements of the SPS accelerator. The architectural design of the new system is presented with special emphasis on how the conflict between safety and availability has been addressed

Tracking the source of the hepatitis B virus-specific CD8 T cells during lamivudine treatment

Lamivudine treatment in chronic hepatitis B leads to the reconstitution of virus-specific T cells in the circulation, but it is not clear whether this is the preferential result of T cell efflux from the liver or lymph nodes. To address this question, the frequency and function of liver-, lymph node-, and blood-derived hepatitis B virus (HBV)-specific CD8 T cells were analyzed in patients treated with lamivudine and undergoing liver transplantation. HBV-specific CD8 T cells, identified in portal lymph nodes, were able to expand in vitro after antigen-specific stimulation and displayed a heterogeneous profile of cytokine production. These findings suggest that the peripherally reconstituted HBV-specific CD8 T cells can originate from precursor cells within lymph nodes

Control and interlock system for the SPS main power converters

The control and interlock system of the main power converters was 20 years old and needed to be replaced. In order to face the shrinking resources of CERN, it was decided to adopt, as far as possible, standard industrial solutions and to contract out the development of the new system to industry. A tender was sent to European firms and the contract was awarded to GTD, a Spanish Engineering Firm, in May 1997. The SPS accelerator restarted in March 98 with the new Control and Interlock System

The Contribution of the Smectic-Nematic Interface to the Surface Energy

The contribution of the smectic-nematic interface to the surface energy of a nematic liquid crystal sample is analyzed. By means of a simple model it is shown that the surface energy depends on the thickness of the region over which the transition smectic-nematic takes place. For perfectly flat substrates this thickness is of the order of the correlation length entering in the transition. An estimate of this contribution shows that it is greater than the one arising from the nematic-substrate interaction. Moreover, it is also shown that the surface energy determined in this way presents a non-monotonic behavior with the temperature.Comment: 10 pages, revte

The grapevine Pectin Methylesterases gene family and its involvement in Botrytis bunch rot control

Plant Pectin Methylesterases (PMEs) represent a group of tissue-specific and developmentally regulated proteins. The gene family is involved in the plant cell wall (CW) remodelling process, by the control of the degree of cell wall pectin methylesterification. Pectin methylesterification also influence the susceptibility to pathogens as Botrytis cinerea (Bc), a necrotrophic fungus responsible of the Botrytis bunch rot in grapevine. In Botrytis, PME as well as other CW degrading enzymes have been identified as virulence factors. To further characterize the PME gene family and its role in the Botrytis bunch rot, the latest genome assembly and annotation were revised and through sequence homology search, a total of 63 PME domain containing proteins were identified, 16 more than a previous identification in grapevine. The in-silico analyses of the family by means of the Vitis gene expression database VESPUCCI as well as Aggregated Gene Co-expression Network approach (AggGCNs) allowed us to identify and enrich gene co-expression modules and build gene co-expression networks. Interestingly, one of the co-expression modules showed a high modulation in presence of Botrytis cinerea infection and particular attention was paid to it. To investigate the contribution of the genes of that module, their expression level in different organs and developmental stages from two grapevine cultivars with divergent Bc susceptibility was investigated. Furthermore, berries were artificially infected with Bc at mature stage to evaluate PME gene expression level and their possible role in the grapevine bunch rot susceptibility. The results obtained contribute to characterize the grapevine PME gene family and the role of specific members in the grapevine-Bc interaction and to select PME genes candidate to the control of Botrytis bunch rot in grapevine

Accessibility and allocation of public parks and gardens in England and Wales: a COVID-19 social distancing perspective

Visiting parks and gardens supports physical and mental health. We quantified access to public parks and gardens in urban areas of England and Wales, and the potential for park crowdedness 22during periods of high use. We combined data from the Office for National Statistics and Ordnance Survey to quantify(i) the number of parks within 500and 1,000metresof urban postcodes (i.e., availability), (ii) the distance of postcodes to the nearest park (i.e., accessibility), and (iii) per-capita space in each park for people living within 1,000m.We26examined variability by city and share of flats. Around 25.4 million people(~87%) can access public parks or gardens within a ten-minute walk, while 3.8 million residents (~13%) live farther away; of these 21% are children and 13% are elderly. Areas with a higher share of flats on average are closer to a park but people living in these areas visit parks that are potentially overcrowded during periods of high use. Such disparity in urban areas of England and Wales becomes particularly evident during COVID-19 pandemic and lockdown when local parks, the only available out-of-home space option, hinder social distancing requirements. Cities aiming to facilitate social distancing while keeping public green spaces safe might require implementing measures such as dedicated park times for different age groups or entry allocation systems that, combined with smartphone apps or drones, can monitor and manage the total number of people using the park