First ice core records of NO3− stable isotopes from Lomonosovfonna, Svalbard

Samples from two ice cores drilled at Lomonosovfonna, Svalbard, covering the period 1957–2009, and 1650–1995, respectively, were analyzed for NO3− concentrations, and NO3− stable isotopes (δ15N and δ18O). Post-1950 δ15N has an average of (−6.9 ± 1.9) ‰, which is lower than the isotopic signal known for Summit, Greenland, but agrees with values observed in recent Svalbard snow and aerosol. Pre-1900 δ15N has an average of (4.2 ± 1.6) ‰ suggesting that natural sources, enriched in the 15 N-isotope, dominated before industrialization. The post-1950 δ18O average of (75.1 ± 4.1) ‰ agrees with data from low and polar latitudes, suggesting similar atmospheric NOy (NOy = NO + NO2 + HNO3) processing pathways. The combination of anthropogenic source δ15N and transport isotope effect was estimated as −29.1 ‰ for the last 60 years. This value is below the usual range of NOx (NOx = NO + NO2) anthropogenic sources which is likely the result of a transport isotope effect of –32 ‰. We suggest that the δ15N recorded at Lomonosovfonna is influenced mainly by fossil fuel combustion, soil emissions and forest fires; the first and second being responsible for the marked decrease in δ15N observed in the post-1950s record with soil emissions being associated to the decreasing trend in δ15N observed up to present time, and the third being responsible for the sharp increase of δ15N around 2000

The CMS Event Builder

The data acquisition system of the CMS experiment at the Large Hadron Collider will employ an event builder which will combine data from about 500 data sources into full events at an aggregate throughput of 100 GByte/s. Several architectures and switch technologies have been evaluated for the DAQ Technical Design Report by measurements with test benches and by simulation. This paper describes studies of an EVB test-bench based on 64 PCs acting as data sources and data consumers and employing both Gigabit Ethernet and Myrinet technologies as the interconnect. In the case of Ethernet, protocols based on Layer-2 frames and on TCP/IP are evaluated. Results from ongoing studies, including measurements on throughput and scaling are presented. The architecture of the baseline CMS event builder will be outlined. The event builder is organised into two stages with intelligent buffers in between. The first stage contains 64 switches performing a first level of data concentration by building super-fragments from fragments of 8 data sources. The second stage combines the 64 super-fragments into full events. This architecture allows installation of the second stage of the event builder in steps, with the overall throughput scaling linearly with the number of switches in the second stage. Possible implementations of the components of the event builder are discussed and the expected performance of the full event builder is outlined.Comment: Conference CHEP0

Using XDAQ in Application Scenarios of the CMS Experiment

XDAQ is a generic data acquisition software environment that emerged from a rich set of of use-cases encountered in the CMS experiment. They cover not the deployment for multiple sub-detectors and the operation of different processing and networking equipment as well as a distributed collaboration of users with different needs. The use of the software in various application scenarios demonstrated the viability of the approach. We discuss two applications, the tracker local DAQ system for front-end commissioning and the muon chamber validation system. The description is completed by a brief overview of XDAQ.Comment: Conference CHEP 2003 (Computing in High Energy and Nuclear Physics, La Jolla, CA

The CMS event builder demonstrator based on Myrinet

The data acquisition system for the CMS experiment at the Large Hadron Collider (LHC) will require a large and high performance event building network. Several switch technologies are currently being evaluated in order to compare different architectures for the event builder. One candidate is Myrinet. This paper describes the demonstrator which has been set up to study a small-scale (8*8) event builder based on a Myrinet switch. Measurements are presented on throughput, overhead and scaling for various traffic conditions. Results are shown on event building with a push architecture. (6 refs)

A software approach for readout and data acquisition in CMS

Traditional systems dominated by performance constraints tend to neglect other qualities such as maintainability and configurability. Object-Orientation allows one to encapsulate the technology differences in communication sub-systems and to provide a uniform view of data transport layer to the systems engineer. We applied this paradigm to the design and implementation of intelligent data servers in the Compact Muon Solenoid (CMS) data acquisition system at CERN to easily exploiting the physical communication resources of the available equipment. CMS is a high-energy physics experiment under study that incorporates a highly distributed data acquisition system. This paper outlines the architecture of one part, the so called Readout Unit, and shows how we can exploit the object advantage for systems with specific data rate requirements. A C++ streams communication layer with zero copying functionality has been established for UDP, TCP, DLPI and specific Myrinet and VME bus communication on the VxWorks real-time operating system. This software provides performance close to the hardware channel and hides communication details from the application programmers. (28 refs)

The experiences of young liver patients transferring from children's to adult services and their support needs for a successful transition

Background: The period of transition from pediatric to adult services represents a time when young people need support, information, and appropriate care in order to successfully move. It is a period that is associated with nonadherence and disengagement with care. Objective: To explore the experiences of young liver transplant recipients transitioning to adult services and determine what they require in order to achieve a successful move. The research also explored the possibility of using a mobile phone application (app) as a tool to support transition. Design: Qualitative approach using novel arts-based focus groups and one-to-one interviews. Participants: Twenty-one young people aged 16 to 25 years, 16 health-care professionals involved in their care, and 7 young people as follow-up. Participants used services provided by the 3 liver centers in England (Leeds, Birmingham, and London). Results: Data highlighted the variability of transition pathways in England for young people moving from child to adult health services. The results showed that they required clear information regarding transition processes including specific medical information and that there was a shortfall in such information. Support was required in the form of a designated transition coordinator or similar specialist who could act as a point of reference and guidance throughout the process. Transitions needed to be individualized and based upon transition readiness rather than age, although the research showed that age cut-offs were still used. Conclusion: Young people welcomed apps to provide information, reminders, contacts, and connections. Future research should explore the efficacy of such apps

The experiences of young liver patients transferring from children's to adult services and their support needs for a successful transition

Background: The period of transition from pediatric to adult services represents a time when young people need support, information, and appropriate care in order to successfully move. It is a period that is associated with nonadherence and disengagement with care. Objective: To explore the experiences of young liver transplant recipients transitioning to adult services and determine what they require in order to achieve a successful move. The research also explored the possibility of using a mobile phone application (app) as a tool to support transition. Design: Qualitative approach using novel arts-based focus groups and one-to-one interviews. Participants: Twenty-one young people aged 16 to 25 years, 16 health-care professionals involved in their care, and 7 young people as follow-up. Participants used services provided by the 3 liver centers in England (Leeds, Birmingham, and London). Results: Data highlighted the variability of transition pathways in England for young people moving from child to adult health services. The results showed that they required clear information regarding transition processes including specific medical information and that there was a shortfall in such information. Support was required in the form of a designated transition coordinator or similar specialist who could act as a point of reference and guidance throughout the process. Transitions needed to be individualized and based upon transition readiness rather than age, although the research showed that age cut-offs were still used. Conclusion: Young people welcomed apps to provide information, reminders, contacts, and connections. Future research should explore the efficacy of such apps