scholarly journals The Metrological Traceability, Performance and Precision of European Radon Calibration Facilities

Author(s):  
Thomas R. Beck ◽  
Andrei Antohe ◽  
Francesco Cardellini ◽  
Alexandra Cucoş ◽  
Eliska Fialova ◽  
...  

An interlaboratory comparison for European radon calibration facilities was conducted to evaluate the establishment of a harmonized quality level for the activity concentration of radon in air and to demonstrate the performance of the facilities when calibrating measurement instruments for radon. Fifteen calibration facilities from 13 different European countries participated. They represented different levels in the metrological hierarchy: national metrology institutes and designated institutes, national authorities for radiation protection and participants from universities. The interlaboratory comparison was conducted by the German Federal Office for Radiation Protection (BfS) and took place from 2018 to 2020. Participants were requested to measure radon in atmospheres of their own facilities according to their own procedures and requirements for metrological traceability. A measurement device with suitable properties was used to determine the comparison values. The results of the comparison showed that the radon activity concentrations that were determined by European calibration facilities complying with metrological traceability requirements were consistent with each other and had common mean values. The deviations from these values were normally distributed. The range of variation of the common mean value was a measure of the degree of agreement between the participants. For exposures above 1000 Bq/m3, the variation was about 4% for a level of confidence of approximately 95% (k=2). For lower exposure levels, the variation increased to about 6%.

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.


Author(s):  
Yuko Komuro ◽  
Yuji Ohta

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.


Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 816
Author(s):  
Kuei-Yuan Hou ◽  
Hao-Yuan Lu ◽  
Ching-Ching Yang

This study aimed to facilitate pseudo-CT synthesis from MRI by normalizing MRI intensity of the same tissue type to a similar intensity level. MRI intensity normalization was conducted through dividing MRI by a shading map, which is a smoothed ratio image between MRI and a three-intensity mask. Regarding pseudo-CT synthesis from MRI, a conversion model based on a three-layer convolutional neural network was trained and validated. Before MRI intensity normalization, the mean value ± standard deviation of fat tissue in 0.35 T chest MRI was 297 ± 73 (coefficient of variation (CV) = 24.58%), which was 533 ± 91 (CV = 17.07%) in 1.5 T abdominal MRI. The corresponding results were 149 ± 32 (CV = 21.48%) and 148 ± 28 (CV = 18.92%) after intensity normalization. With regards to pseudo-CT synthesis from MRI, the differences in mean values between pseudo-CT and real CT were 3, 15, and 12 HU for soft tissue, fat, and lung/air in 0.35 T chest imaging, respectively, while the corresponding results were 3, 14, and 15 HU in 1.5 T abdominal imaging. Overall, the proposed workflow is reliable in pseudo-CT synthesis from MRI and is more practicable in clinical routine practice compared with deep learning methods, which demand a high level of resources for building a conversion model.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 879
Author(s):  
Rosanna Floris ◽  
Gabriele Sanna ◽  
Cecilia Teodora Satta ◽  
Carlo Piga ◽  
Francesco Sanna ◽  
...  

Fish populations play an active role in the maintenance of aquatic ecosystems biodiversity. Their intestinal microbiota and fillet chemistry depend on abiotic and biotic factors of the water environments that they inhabit. The present study investigated the grey mullets’ gut microbiota from a transitional aquatic ecosystem (Santa Giusta Lagoon, Sardinia, Italy) by a multidisciplinary approach which refers the results of (1) gut cultivable microbiota analyses (MA), (2) the trace metal assessment of fish muscle (TM), (3) the physico-chemical water monitoring (PC). MA detected the greatest number of total aerobic heterotrophic bacteria, Enterobacteriaceae and coliforms in Autumn (mean values 1.3 × 105, 2.4 × 104, 1.1 × 104 cfu g−1, respectively) when the accumulated rain and mean values of nutrients (reactive phosphorous and silica) were the highest. Marine bacteria were more numerous in Summer (mean value 7.4 × 105 cfu g−1) when the highest mean values of water temperature and salinity were registered. The gut bacteria were identified as Pseudomonas spp. (64%), Aeromonas spp. (17%), Ochrobactrum pseudogrignonense (10%), Providencia spp. (5%), Enterobacter ludwigii (2%) and Kocuria tytonicola (2%). TM showed that Ca, Na, B and Ni increased their concentrations in Winter while maxima of P, Zn, Cu and Fe were found in muscles of fish sampled in Summer. This study highlighted that the fish intestinal microbiota and metal composition of the fillet reflected the seasonal aquatic environmental variability.


1978 ◽  
Vol 91 (1) ◽  
pp. 13-16 ◽  
Author(s):  
D. I. Givens ◽  
J. R. Hopkins

SummaryA total of 225 herbage samples were taken from two areas with a history of bovine hypocupraemia and examined for their Cu, Mo, total S, Zn, Fe and Cd content.In general, the concentrations of Cu and Mo (mean values 10·4 and 1·6 mg/kgD.M. respectively) were normal, as were those of Zn, Fe and Cd (mean values 43, 255 and 0–59 mg/kg D.M. respectively). The total S concentrations (mean value 3·5 g/kg D.M.) were, however, higher than found by some other workers.The concentrations of available herbage Cu were calculated using the following relationship of Suttle & McLauchlan (1976):logTA Cu = –0·0019 Mo–0·0755 S–0·0131 Mo × S–1·153,where TA Cu is the true availability of Cu, and Mo and total sulphur (S) are dietary concentrations as mg/kg D.M. and g/kg D.M. respectively. Animal requirements for available Cu were derived from estimates of the factorial Cu requirements of various classes of livestock, and when these were compared with the calculated concentrations of available Cu in the herbage they provided a possible explanation for the widespread hypocupraemia experienced in these areas.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1079.1-1079
Author(s):  
I. Yoshii

Background:Boolean remission criteria is one most popular and stringent criteria in treating patient with rheumatoid arthritis (RA), because it may guarantees a stable clinical course after attaining remission.Objectives:Impact of time span from initiation to achieving Boolean remission on maintaining disease activity, daily activities, and quality of life after attaining Boolean remission was investigated from daily clinical practice data.Methods:685 patients with RA since August 2010 under the T2T strategy were treated. They were monitored for their TJC, SJC, PGA, EGA, CRP, and disease activity indices such as CDAI, SDAI, DAS28, and Boolean criteria at every visit. HAQ-DI score, pain score using visual analog scale (PS-VAS), and EQ-5D were also monitored, and the quality of life score (QOLS) calculated from EQ-5D was determined at every visit from the time of diagnosis (baseline).Of 685 patients, 465 patients had achieved Boolean remission >1 times, and were consecutively followed up for >3 years. These patients were enrolled in the study. Time span from the first visit to first Boolean remission was calculated. The relationship between the time span and each of background parameters, and the relationship between the time span and each of the mean values of the SDAI score, HAQ score, PS-VAS, SHS, and QOLS at the first Boolean remission and thereafter was evaluated statistically.Patients were subsequently divided into the G ≤ 6 and G > 6 groups based on the achievement of first Boolean remission within two groups: time span G ≤ 6 months and G > 6 months. The two groups were compared with regard to the SDAI score, HAQ score, PS-VAS, SHS, and QOLS at first visit and at the time of first Boolean remission, and the mean values of these parameters after remission were evaluated statistically. Moreover, changes of these parameters and the mean Boolean remission rate after the first remission, and SDAI remission rate at the first Boolean remission to thereafter were compared between the two groups statistically.Results:Out of 465 patients, females comprised 343 (73.7%), and the mean age was 67.8 years (range, from 21–95 years). The mean disease duration at first visit was 6.1 years (range, from 1 months–45 years). The mean follow up length was 88.1 months (range: 36–122 months; median: 85 months) and mean time span from the first visit to the first Boolean remission was 8.1 months. The mean SDAI score, HAQ score, PS-VAS, and the QOLS at first visit were 13.3, 0.467, 33.2, and 0.834, respectively. Among the study parameters, PS-VAS and QOLS were significantly correlated with the time span. For parameters at the first Boolean remission, HAQ-DI score, PS-VAS, and QOLS demonstrated significant correlation with the time span, whereas SDAI, HAQ-DI score, PS-VAS, SHS, and QOLS after the Boolean remission demonstrated significant correlation with the time span.The comparison between the G ≤ 6 and the G > 6 groups revealed that the disease duration, HAQ score, and PS-VAS at baseline in the G > 6 were significantly higher than that in the G ≤ 6 group, and QOLS in the G ≤ 6 group was significantly higher than that in the G > 6 group at baseline. Similarly, the HAQ score and PS-VAS at the first Boolean remission in the G > 6 group were significantly higher than that in the G ≤ 6 group, whereas QOLS in the G ≤ 6 group demonstrated no significant difference compared with that in the G > 6 group.The mean value of the SDAI score after the first Boolean remission in the G > 6 group was significantly higher than that in the G ≤ 6 group. Similarly, the SDAI score, HAQ score, and PS-VAS after the first Boolean remission in the G > 6 group were also significantly higher than those in the G ≤ 6 group, and the mean value of the QOLS in the G ≤ 6 group were significantly higher than that in the G > 6 group. The Boolean remission rate and SDAI remission rate after the first Boolean remission were significantly higher in the G ≤ 6 group than those in the G > 6 group.Conclusion:Attaining Boolean remission ≤ 6 months for RA has significant benefit for more stable disease control, that leads good maintenance of ADL.Disclosure of Interests:None declared


2012 ◽  
Vol 8 (S290) ◽  
pp. 327-328
Author(s):  
D. H. Wang ◽  
L. Chen

AbstractWith kilohertz quasi-periodic oscillation (kHz QPO) sources in neutron star low mass X-ray binaries (NS-LMXBs) published up to now, we analyze the centroid frequency (ν) distribution of twin kHz QPOs. We find that Atoll and Z sources show the similar distributions of ν1 and ν2, which indicate that twin kHz QPOs may be the common property of NS-LXMBs and have the similar physical origins. The mean values of ν1 and ν2 in Atoll sources are higher than those in Z sources, and we consider that this may because the QPO signals are sheltered by the thicken accretion disk or corona in Z sources. The maximums of ν2 in both Atoll and Z sources are the same order as the Keplerian orbital frequency of the NS surface, so kHz QPOs could occur near the NS surface.


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