112 research outputs found
Method for High Accuracy Multiplicity Correlation Measurements
Multiplicity correlation measurements provide insight into the dynamics of
high energy collisions. Models describing these collisions need these
correlation measurements to tune the strengths of the underlying QCD processes
which influence all observables. Detectors, however, often possess limited
coverage or reduced efficiency that influence correlation measurements in
obscure ways. In this paper, the effects of non-uniform detection acceptance
and efficiency on the measurement of multiplicity correlations between two
distinct detector regions (termed forward-backward correlations) are derived.
An analysis method with such effects built-in is developed and subsequently
verified using different event generators. The resulting method accounts for
acceptance and efficiency in a model independent manner with high accuracy
thereby shedding light on the relative contributions of the underlying
processes to particle production.Comment: 28 pages, 13 figures. Updated for having pseudorapidity dependent
efficiency gradient
Contents of α-tocopherol and β-carotene in grasses and legumes harvested at different maturities
Concentrations of α-tocopherol and β-carotene in forage species at various maturities were studied in Scandinavia. Red clover (RC)/timothy (TI), RC/meadow fescue (MF), and
birdsfoot trefoil (BT)/TI mixtures were grown in Skara and Umeå, Sweden. RC/TI,RC/perennial ryegrass (PR), white clover/PR and BT/TI were grown in Foulum, Denmark. Forages in Sweden were cut one week before heading (BH), at heading and one week after heading of TI. The regrowth was cut six and eight weeks after each harvest in the spring growth cycle. In Denmark, one first harvest and three regrowths were taken. Results from Skara and Foulum are presented. Highest concentrations of α-tocopherol and β-carotene (mg
kg-1 DM) in legumes were found in BT grown in Skara (49.8 and 69.6 in spring growth cycle,48.1 and 79.8 in regrowth) and in Foulum (81.3 and 89.2). MF had more α-tocopherol and β-carotene than TI in the spring growth cycle (73.5 and 54.2 vs. 46.9 and 43.0 mg kg-1 DM). Highest concentrations of vitamins in the regrowth were found six weeks after BH with 71.8 and 104.8 mg α-tocopherol and 99.6 and 73.1 mg β-carotene kg-1 DM in legumes and grasses,respectively
Vitaminer og fedtsyrer i hø og ensilage – hvad sker der vid forvejring og lagring?
For at undersøge stabiliteten af vitaminer i moderne ensilage- og høproduktion, har FØJO III projektet ECOVIT, igennem to vækstår, målt vitaminindholdet i forskellige græsmarksafgrøder ved forskellige høsttidspunkter og sletintervaller. Resultaterne viser, at det største tab af vitaminer og umættede fedtsyrer sker i forbindelse med forvejringen, mens tabet i lagringsperioden
er begrænset
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 m^3 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.Comment: 55 pages, 82 figure
The Swedish Spine Register: development, design and utility
The Swedish Spine Register enables monitoring of surgical activities focusing on changes in trends over time, techniques utilized and outcome, when implemented in general clinical practice. Basic requirements for a prosperous register are unity within the profession, mainly patient-based documentation and a well functioning support system. This presentation focuses on the development and design of the register protocol, problems encountered and solutions found underway. Various examples on how the results can be presented and utilized are given as well as validation. Register data demonstrate significant gender differences in lumbar disc herniation surgery with females having more pain, lower quality of life and more pronounced disability preoperatively while improvement after surgery is similar between genders. Quality of life after surgery for degenerative disorders is significantly improved for disc herniation, stenosis, spondylolisthesis and disc degenerative disorders. Over the last 10 years, surgical treatment for spinal stenosis has increased gradually while disc herniation surgery decreases regarding yearly number of procedures. An added function to the register enables more complex prospective clinical studies to include register data together with data suitable for the individual study. A common core set of demographic, surgical and outcome parameters would enable comparisons of clinical studies within and between nations
Cost effectiveness of disc prosthesis versus lumbar fusion in patients with chronic low back pain: randomized controlled trial with 2-year follow-up
This randomized controlled health economic study assesses the cost-effectiveness of the concept of total disc replacement (TDR) (Charité/Prodisc/Maverick) when compared with the concept of instrumented lumbar fusion (FUS) [posterior lumbar fusion (PLF) /posterior lumbar interbody fusion (PLIF)]. Social and healthcare perspectives after 2 years are reported. In all, 152 patients were randomized to either TDR (n = 80) or lumbar FUS (n = 72). Cost to society (total mean cost/patient, Swedish kronor = SEK, standard deviation) for TDR was SEK 599,560 (400,272), and for lumbar FUS SEK 685,919 (422,903) (ns). The difference was not significant: SEK 86,359 (−45,605 to 214,332). TDR was significantly less costly from a healthcare perspective, SEK 22,996 (1,202 to 43,055). Number of days on sick leave among those who returned to work was 185 (146) in the TDR group, and 252 (189) in the FUS group (ns). Using EQ-5D, the total gain in quality adjusted life years (QALYs) over 2 years was 0.41 units for TDR and 0.40 units for FUS (ns). Based on EQ-5D, the incremental cost-effectiveness ratio (ICER) of using TDR instead of FUS was difficult to analyze due to the “non-difference” in treatment outcome, which is why cost/QALY was not meaningful to define. Using cost-effectiveness probabilistic analysis, the net benefit (with CI) was found to be SEK 91,359 (−73,643 to 249,114) (ns). We used the currency of 2006 where 1 EURO = 9.26 SEK and 1 USD = 7.38 SEK. It was not possible to state whether TDR or FUS is more cost-effective after 2 years. Since disc replacement and lumbar fusion are based on different conceptual approaches, it is important to follow these results over time
Chronic diseases are strongly associated with sickness absences in a sample of Italian public employees
Surface Energy Budgets of Arctic Tundra During Growing Season
This study analyzed summer observations of diurnal and seasonal surface energy budgets across several monitoring sites within the Arctic tundra underlain by permafrost. In these areas, latent and sensible heat fluxes have comparable magnitudes, and ground heat flux enters the subsurface during short summer intervals of the growing period, leading to seasonal thaw. The maximum entropy production (MEP) model was tested as an input and parameter parsimonious model of surface heat fluxes for the simulation of energy budgets of these permafrost‐underlain environments. Using net radiation, surface temperature, and a single parameter characterizing the thermal inertia of the heat exchanging surface, the MEP model estimates latent, sensible, and ground heat fluxes that agree closely with observations at five sites for which detailed flux data are available. The MEP potential evapotranspiration model reproduces estimates of the Penman‐Monteith potential evapotranspiration model that requires at least five input meteorological variables (net radiation, ground heat flux, air temperature, air humidity, and wind speed) and empirical parameters of surface resistance. The potential and challenges of MEP model application in sparsely monitored areas of the Arctic are discussed, highlighting the need for accurate measurements and constraints of ground heat flux.Plain Language SummaryGrowing season latent and sensible heat fluxes are nearly equal over the Arctic permafrost tundra regions. Persistent ground heat flux into the subsurface layer leads to seasonal thaw of the top permafrost layer. The maximum energy production model accurately estimates the latent, sensible, and ground heat flux of the surface energy budget of the Arctic permafrost regions.Key PointThe MEP model is parsimonious and well suited to modeling surface energy budget in data‐sparse permafrost environmentsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150560/1/jgrd55584.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150560/2/jgrd55584_am.pd
Influence of seasonality and vegetation type on suburban microclimates
Urbanization is responsible for some of the fastest rates of land-use change around the world, with important consequences for local, regional, and global climate. Vegetation, which represents a significant proportion of many urban and suburban landscapes, can modify climate by altering local exchanges of heat, water vapor, and CO2. To determine how distinct urban forest communities vary in their microclimate effects over time, we measured stand-level leaf area index, soil temperature, infrared surface temperature, and soil water content over a complete growing season at 29 sites representing the five most common vegetation types in a suburban neighborhood of Minneapolis–Saint Paul, Minnesota. We found that seasonal patterns of soil and surface temperatures were controlled more by differences in stand-level leaf area index and tree cover than by plant functional type. Across the growing season, sites with high leaf area index had soil temperatures that were 7°C lower and surface temperatures that were 6°C lower than sites with low leaf area index. Site differences in mid-season soil temperature and turfgrass ground cover were best explained by leaf area index, whereas differences in mid-season surface temperature were best explained by percent tree cover. The significant cooling effects of urban tree canopies on soil temperature imply that seasonal changes in leaf area index may also modulate CO2 efflux from urban soils, a highly temperature-dependent process, and that this should be considered in calculations of total CO2 efflux for urban carbon budgets. Field-based estimates of percent tree cover were found to better predict mid-season leaf area index than satellite-derived estimates and consequently offer an approach to scale up urban biophysical properties
Psychoeducation to facilitate return to work in individuals on sick leave and at risk of having a mental disorder: protocol of a randomised controlled trial
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