The f_LT Response Function of D(e,e'p)n at Q^2=0.33(GeV/c)^2

The interference response function f_LT (R_LT) of the D(e,e'p)n reaction has been determined at squared four-momentum transfer Q^2 = 0.33 (GeV/c)^2 and for missing momenta up to p_miss= 0.29 (GeV/c). The results have been compared to calculations that reproduce f_LT quite well but overestimate the cross sections by 10 - 20% for missing momenta between 0.1 (GeV/c) and 0.2 (GeV/c) .Comment: 12 Pages, 10 figure

A measurement of the axial form factor of the nucleon by the p(e,e'pi+)n reaction at W=1125 MeV

The reaction p(e,e'pi+)n was measured at the Mainz Microtron MAMI at an invariant mass of W=1125 MeV and four-momentum transfers of Q^2=0.117, 0.195 and 0.273 (GeV/c)^2. For each value of Q^2, a Rosenbluth separation of the transverse and longitudinal cross sections was performed. An effective Lagrangian model was used to extract the `axial mass' from experimental data. We find a value of M_A=(1.077+-0.039) GeV which is (0.051+-0.044) GeV larger than the axial mass known from neutrino scattering experiments. This is consistent with recent calculations in chiral perturbation theory.Comment: 14 pages, 5 figures, uses elsart.cl

Temporal Regulation of Rapamycin on Memory CTL Programming by IL-12

Mammalian target of rapamycin (mTOR) is a master regulator of cell growth. Recent reports have defined its important role in memory cytotoxic T lymphocyte (CTL) differentiation in infections and memory programming. We report that rapamycin regulated memory CTL programming by IL-12 to a similar level in a wide range of concentrations, and the enhanced memory CTLs by rapamycin were functional and provided similar protection against Listeria Monocytogenes challenge compared to the control. In addition, rapamycin-experienced CTLs went through substantially enhanced proliferation after transfer into recipients. Furthermore, the regulatory function of rapamycin on CD62L expression in memory CTLs was mainly contributed by the presence of rapamycin in the first 24-hr of stimulation in vitro, whereas the effective window of rapamycin on the size of memory CTLs was determined between 24 to 72 hrs. In conclusion, rapamycin regulates IL-12-driven programming of CTLs to a similar level in a wide range of concentrations, and regulates the phenotype and the size of memory CTLs in different temporal windows

Beryllium-7 correlations in total deposition (dry and wet) measured in Serbia and Slovenia

Beryllium-7 is a natural radionuclide whose specific activity at the surface strongly depends on transport history from the upper atmosphere where this isotope is produced. Since the major removal mechanism of beryllium-7 from the atmosphere is wet deposition, local meteorological factors also play an important role in its abundance at the surface. In this analysis we present the beryllium-7 correlations in total deposition (dry and wet) measured in three locations: Belgrade, the capital of Serbia; Ljubljana, the capital of Slovenia; and Krško, a town in eastern Slovenia where a nuclear power plants located. Air distance between Belgrade and Ljubljana is about 490 km, while Krško lies roughly between them, and is less than 80 km away from Ljubljana. The data in our analysis cover the 1995- 2015 period. The beryllium-7 specific activities were measured by standard gamma spectrometry at the Vinča Institute and Jožef Stefan Institute. A comparison of the three beryllium-7 records in total deposition shows some differences between the measurement sites. For example, the maximum beryllium-7 concentrations in Belgrade are noted in June, while in Ljubljana and Krško, the maximum is observed in August. However, in both cases, the minimum beryllium-7 concentrations occur five months after the maximum, i.e. in November in Vinča, and in February in Ljubljana and Krško. Further, the highest Pearson's linear correlation coefficient (r) is obtained for the LjubljanaKrško records (r=0.68). This strong linear correlation decreases down to a weak correlation of r=0.35 and r=0.30for the Belgrade-Ljubljana and Belgrade-Krško records, respectively

Characteristics of radioactivity in the surface air along the 45°N zonal belt in South-Eastern Europe

This study investigates the beryllium-7, lead-210 and caesium-137 activity concentrations in aerosol filter samples collected monthly along the 45°N zonal belt over 1991–2019. Sampling was performed in three locations, one in Serbia and two in Slovenia, and the Slovenian data records are published here for the first time. The activity concentrations were determined by standard gamma spectrometry. The obtained results are in general agreement with the literature data for Europe. The data sets at different sites display similarities in measurement ranges, overall means and seasonal cycles. Still, statistical tests show significant differences among the radionuclides’ concentrations across the locations. To investigate underlying processes that affect radioactivity in the surface air in this region, multivariate statistical concepts are applied to the radionuclides’ concentrations and local meteorological parameters. Discriminant analysis shows that all three sites are well separated from each other. Principal component analysis gives common pattern of interconnection between the observables: temperature has a stronger influence on the behaviour of beryllium-7 and lead-210 than that of caesium-137, but a negative correlation of the radionuclides’ concentrations with precipitation seems the strongest for caesium-137. Principal component analysis also shows local differences in the degree of relationship between the meteorological parameters and activity concentrations of the investigated radionuclides. This is an important finding for future atmospheric transport studies

Interlaboratory comparison on 137Cs activity concentration in fume dust

A comparison was conducted, between 11 European National Metrology Institutes and EC-JRC, on measurement of 137Cs activity concentration in fume dust. As comparison material an activity standard produced from real contaminated fume dust was used. The standard material consisted of 13 samples of compressed fume dust, each of 50 g mass and of well-defined cylindrical geometry (diameter 69.5 mm and height 18.7 mm). The material contained 137Cs and 60Co of reference activity concentrations of (9.72 ± 0.10) Bq/g and (0.450 ± 0.018) Bq/g, respectively, determined using the comparison results. The organisation and results of the intercomparison, as well as the process of obtaining reliable reference values are presented.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Systematic influences on the areas of peaks in gamma-ray spectra, having a large statistical uncertainty

21st International Conference on Radionuclide Metrology and its Applications; May 15-19, Buenos Aires, Argentina, 2017