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[en] Long-period oscillations have been searched in the time series of the daily minimum, mean and maximum temperatures measured in Modena, Italy, during the years 1869-1976. By assuming only one oscillation present, the amplitude and its statistical uncertainty have been estimated by means of a fitting procedure which takes into account the stochastic variability of the daily temperatures. The period of the long-term oscillations has been chosen to be an integer number of years (from 2 up to 36). This choice and the fit performed over a suitable number of years (the maximum possible multiple of the period) ensure a numerical stable solution and a negligible correlation between the long-period oscillation and the annual and seasonal oscillations present in the time series. The instrumental uncertainty of the long-period amplitude has been also evaluated. Within the overall uncertainty, no reliable evidence exists on single long-period oscillations. (author)

[en] Measurement of radionuclides from environmental samples includes a wide variety of matrix compositions and densities. To improve the traceability of environmental monitoring, LNE-LNHB intends to produce mixed γ-ray reference materials with a known mass activity and a composition as representative as possible of real environmental samples. This paper describes the preparation and characterization of a low density treated grass matrix spiked with mixed γ-emitters. This material was used in a proficiency test exercise whose results are presented. - Highlights: • Preparation of a low density treated grass matrix spiked with mixed gamma emitters. • Spiking yield close to 100% regardless of the radionuclide considered. • Characterization of the matrix in terms of density, particle–size, moisture content. • Reference values and results of homogeneity tests are given. • Results of a proficiency test organized with this matrix are presented

[en] A method for the estimation of the concentrations of radon daughters in air is given. The method is based on alpha spectrometric counting measurements performed either during or after the dust collection with an electrostatic precipitator. The relations between measured counts and concentrations in air of the collected nuclides (RaA, RaB and RaC) are obtained assuming a constant collection rate and a linear collection rate model. It turns out that the less sophisticated model gives more satisfactory estimations of the parameters. (Auth.)

[en] The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on megakaryocytopoiesis and platelet production was investigated in patients with normal hematopoiesis. Three findings indicated that GM-CSF plays a role in megakaryocytopoiesis. During treatment with GM-CSF (recombinant mammalian, glycosylated; Sandoz/Schering-Plough, 5.5 micrograms protein/kg/d, subcutaneously for 3 days) the percentage of megakaryocyte progenitors (megakaryocyte colony forming unit [CFU-Mk]) in S phase (evaluated by the suicide technique with high 3H-Tdr doses) increased from 31% +/- 16% to 88% +/- 11%; and the maturation profile of megakaryocytes was modified, with a relative increase in more immature stage I-III forms. Moreover, by autoradiography (after incubation of marrow cells with 125I-labeled GM-CSF) specific GM-CSF receptors were detectable on megakaryocytes. Nevertheless, the proliferative stimulus induced on the progenitors was not accompanied by enhanced platelet production (by contrast with the marked granulomonocytosis). It may be suggested that other cytokines are involved in the regulation of the intermediate and terminal stages of megakaryocytopoiesis in vivo and that their intervention is an essential prerequisite to turn the GM-CSF-induced proliferative stimulus into enhanced platelet production

[en] We analyze the effective actions of anomalous models in which a four-dimensional version of the Green-Schwarz mechanism is invoked for the cancellation of the anomalies, and we compare it with those models in which gauge invariance is restored by the presence of a Wess-Zumino term. Some issues concerning an apparent violation of unitarity of the mechanism, which requires Dolgov-Zakharov poles, are carefully examined, using a class of amplitudes studied in the past by Bouchiat-Iliopoulos-Meyer (BIM), and elaborating on previous studies. In the Wess-Zumino case we determine explicitly the unitarity bound using a realistic model of intersecting branes (the Madrid model) by studying the corresponding BIM amplitudes. This is shown to depend significantly on the Stueckelberg mass and on the coupling of the extra anomalous gauge bosons and allows one to identify standard-model-like regions (which are anomaly-free) from regions where the growth of certain amplitudes is dominated by the anomaly, separated by an inflection point, which could be studied at the LHC. The bound can even be around 5-10 TeV for a Z' mass around 1 TeV and varies sensitively with the anomalous coupling. The results for the WZ case are quite general and apply to all the models in which an axion-like interaction is introduced as a generalization of the Peccei-Quinn mechanism, with a gauged axion. (orig.)

[en] Experiments were performed to verify the possible influence of the temperature and source matrix on the half-life of ²¹⁰Po. Since the precise measurement of the activity of an α-emitting source at cryogenic temperature is far from trivial, a simpler approach was used: the activity of a ²¹⁰Po source was measured at ambient temperature, but in between the measurements, the source was cooled down during a few weeks in a liquid helium Dewar. A ²¹⁰Po solid source was prepared by electro-deposition on a silver plate. The activity of this source was first measured at room temperature, using the defined solid angle α measurement method. The source was then placed in a specific gastight container inside a liquid helium bath at 4 K during 28 days. Then the source was heated up and measured again using the same instrument in the same geometric conditions. The same experiment was repeated with the source coated with a thin layer of silver, in order to be sure that the radioactive material was fully embedded inside the metallic matrix. Our experiments showed no evidence of ²¹⁰Po half-life change at low temperature. A reduction of the half-life of ²¹⁰Po by 6.3% at low temperature, as claimed by , would have lead to a decay-corrected activity reduction of about 1% after 29 days, which would have been easily detectable. The paper describes the steps of this experiment and gives a detailed uncertainty budget for the measurements. The half-life of ²¹⁰Po obtained in each measurement is compared with the evaluated value of (138.3763±0.0017) d.

[en] Quantitative solid sources are used widely in the field of radionuclide metrology. With the aim to improve the detection efficiency for electrons and x-rays, a comparative study between two source drying techniques has been undertaken at LNE-Laboratoire National Henri Becquerel (LNE-LNHB, France). In this paper, freeze-drying using commercial equipment is compared with a system of drying using hot jets of nitrogen developed at Institute for Reference Materials and Measurements (IRMM, Belgium). In order to characterize the influence of self-absorption, the detection efficiencies for ⁵¹Cr sources have been measured by coincidence counting and photon spectrometry