The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb–Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report.publishedVersio

The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

-The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb–Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report

First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged-particle pseudorapidity density at root s=900 GeV

-On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range vertical bar eta vertical bar S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase

The proximate composition of three marine pelagic fish: blue whiting (Micromesistius poutassou), boarfish (Capros aper) and Atlantic herring (Clupea harengus)

peer reviewedThis study presents data from an in-depth proximate compositional analysis of three marine fish species: blue whiting (Micromesistius poutassou), boarfish (Capros aper) and Atlantic herring (Clupea harengus). These fish contained significant amounts of protein (16–17%), lipids (4–11%) and minerals (2–6% ash). The proteins, particularly from boarfish, had close to optimum amino acid profiles for human and fish nutrition. They compared favourably with other fish species in terms of total lipids and relative concentration of the omega-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid (11.8–13.3% and 5.9–8.1% in triacylglycerols [TG] and 24.6–35.4% and 5.8–12.0% in phospholipids [PL]). Atlantic herring had the highest lipid content among the three fish and was found to contain high levels of PL poly-unsaturated fatty acids, including omega-3 fatty acids. Minerals detected in the fish included calcium (272–1,520 mg/100 g), phosphorus (363–789 mg/100 g), iron (1.07–2.83 mg/100 g), magnesium (40.70–62.10 mg/100 g), potassium (112.00–267.00 mg/100 g), selenium (0.04–0.06 mg/100 g), sodium (218.00–282.00 mg/100 g) and zinc (1.29–5.57 mg/100 g). Boarfish had the highest ash fraction and also the highest levels of all the minerals, except potassium. Atlantic herring had considerably lower mineral content compared with the other two species and, levels detected were also lower than those reported in previously published studies. Heavy metals contents were quantified, and levels were significantly below the maximum allowable limits for all elements except arsenic, which ranged from 1.34 to 2.44 mg/kg in the three fish species. Data outlined here will be useful for guiding product development. Future studies would benefit from considering catch season, sex and developmental stage of the fish

Socio-economic factors influencing the development of end-stage renal disease in people with Type 1 diabetes - a longitudinal population study

Aims: The development of end-stage renal disease (ESRD) in Type 1 diabetes is multifactorial. Familial socio-economic factors may influence adherence to and understanding of diabetes treatment, and also general health behaviour. We investigate how parental and personal education level and exposure to low economic status, indicated by the need for income support, influence the development of ERSD caused by Type 1 diabetes.Methods: Participants were retrieved from the nationwide Swedish Childhood Diabetes Registry, which was linked to the Swedish Renal Registry, to find people with ESRD caused by Type 1 diabetes, and to Statistic Sweden to retrieve longitudinal socio-economic data on participants and their parents. Data were analysed using Cox regression modelling.Results: Of 9287 people with diabetes of duration longer than 14 years, 154 had developed ESRD due to diabetes. Median diabetes duration (range) for all participants was 24.2 years (14.0-36.7 years). Low maternal education ( 12 years) more than doubled the risk of developing ESRD, hazard ration (HR) = 2.9 [95% confidence interval (95% CI): 1.7-4.8]. For people with a low personal level of education HR was 5.7 (3.4-9.5). In an adjusted model, the person's own education level had the highest impact on the risk of ESRD. If at least one of the parents had ever received income support the HR was 2.6 (1.9-3.6).Conclusions: Socio-economic factors, both for the parents and the person with diabetes, have a strong influence on the development of ESRD in Type 1 diabetes. It is important for caregivers to give enough support to more vulnerable people and their families.</p

Information content of IFRS versus GAAP financial statements

Purpose This study aims to determine whether financial statement users suffered a significant loss of information when, in November 2007, the SEC dropped the requirement for foreign private issuers using International Financial Reporting Standards (“IFRS firms”) to reconcile their financial statements to US generally accepted accounting principles (GAAP). Design/methodology/approach The study investigates whether analyst forecast errors and forecast dispersion increased for IFRS firms to a greater extent than for US GAAP firms after the Securities and Exchange Commission (SEC) dropped the reconciliation requirement. Using a treatment group comprised of IFRS firms and a matched sample of US GAAP firms, this study uses regression analyses to compare forecast errors and dispersion for the last fiscal year the reconciliation was available and the first fiscal year during which the reconciliation was unavailable to analysts. Findings The study finds evidence that forecast errors for IFRS firms exhibited no systematic change after the reconciliation was no longer available for analysts covering those firms. Thus, it does not appear that dropping the reconciliation requirement was associated with a change in forecast accuracy. However, the study does find evidence of increased dispersion in the IFRS firms’ forecasts relative to their US GAAP counterparts after the reconciliation requirement was dropped. Practical implications These findings have implications for evaluating the Securities and Exchange Commission’s 2007 decision to eliminate the reconciliation for IFRS firms. Specifically, the Securities and Exchange Commission’s decision does not appear to have significantly altered analysts’ information environments. Originality/value This paper contributes to the understanding of how a group of sophisticated financial statement users adapt to different sets of accounting standards. </jats:sec