Sub-millimeter nuclear medical imaging with high sensitivity in positron emission tomography using beta-gamma coincidences

We present a nuclear medical imaging technique, employing triple-gamma trajectory intersections from beta^+ - gamma coincidences, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced requirement of reconstructed intersections per voxel compared to a conventional PET reconstruction analysis. This '$\gamma$-PET' technique draws on specific beta^+ - decaying isotopes, simultaneously emitting an additional photon. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize this technique, Monte-Carlo simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in each direction for the visualization of a 22Na point source. Only 40 intersections are sufficient for a reliable sub-millimeter image reconstruction of a point source embedded in a scattering volume of water inside a voxel volume of about 1 mm^3 ('high-resolution mode'). Moreover, starting with an injected activity of 400 MBq for ^76Br, the same number of only about 40 reconstructed intersections are needed in case of a larger voxel volume of 2 x 2 x 3~mm^3 ('high-sensitivity mode'). Requiring such a low number of reconstructed events significantly reduces the required acquisition time for image reconstruction (in the above case to about 140 s) and thus may open up the perspective for a quasi real-time imaging.Comment: 17 pages, 5 figutes, 3 table

Effect of Vapor-Liquid Equilibrium Data on the Design of Separation Sequences by Distillation

An evaluation of the effect of vapor-liquid equilibrium experimental data on the design of separation sequences by distillation was done using computer simulation. Separation of a mixture of ace-tone-chloroform-benzene was chosen as an example problem. Two sequences were compared. To quantify the thermodynamic data uncertainties for each se-quence two sets of binary vapor-liquid equilibrium data were chosen. These two sets of data were used to generate simulation cases as in classical two-level fac-torial design of experiments. A third set of binary va-por-liquid experimental data allows comparing phase liquid models. For the two-column sequence, analysis done to each column alone or to the whole sequence gave the same results. In the three-column sequence, results were different and simulation of the whole se-quence gave a complete different account that simula-tion of each column alone.Fil: Parodi, C. A.. Universidad Nacional del Litoral; ArgentinaFil: Campanella, Enrique Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

An operational flash-flood forecasting chain applied to the test cases of the EU project HYDROPTIMET

International audience The application of a flash-flood prediction chain, developed by CIMA, to some testcases for the Tanaro river basin in the framework of the EU project HYDROPTIMET is presented here. The components of the CIMA chain are: forecast rainfall depths, a stochastic downscaling procedure and a hydrological model. Different meteorological Limited Area Models (LAMs) provide the rainfall input to the hydrological component. The flash-flood prediction chain is run both in a deterministic and in a probabilistic configuration. The sensitivity of forecasting chain performances to different LAMs providing rainfall forecasts is discussed. The results of the application show how the probabilistic forecasting system can give, especially in the case of convective events, a valuable contribution in addressing the uncertainty at different spatio-temporal scales involved in the flash flood forecasting problem in small and medium basins with complex orography

Thoracic aorta cardiac-cycle related dynamic changes assessed with a 256-slice CT scanner

Objective: The aim of our study was to demonstrate whether the dynamic changes previously documented at the ascending and abdominal aorta are replicated at the thoracic aorta. Methods and results: A consecutive series of thirty patients referred to our institution to undergo CT angiography of the thoracic aorta (CTA) constituted the study population. Patients with diffuse aortic atherosclerosis were excluded from the analysis. All studies were acquired with a 256-MDCT scanner and ECG-gating was performed in all cases. Two orthogonal imaging planes (maximal and minimal diameters) were obtained at three different levels of the descending thoracic aorta, using the distance from the left subclavian artery as proximal landmark: 10, 40, and 80 mm distance. The mean age was 58.9±15.7 years and 16 (53%) patients were male. Descending aorta measurements at 10, 40, and 80 mm distance from the left subclavian artery were all significantly larger within the systolic window (P<0.01 for all comparisons). Measurements of the maximal diameter were systematically larger than the minimal diameters among all aortic positions including ungated, systolic, and diastolic measurements (P<0.05 for all comparisons). Conclusions: The main finding of our pilot investigation was that the thoracic descending aorta undergoes significant conformational changes during the cardiac cycle, irrespective from the distance from the left subclavian artery.Fil: Carrascosa, Patricia. Diagnóstico Maipú; ArgentinaFil: Capuñay, Carlos. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnóstico Maipú; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnóstico Maipú; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sagarduy, María Inés. Diagnóstico Maipú; ArgentinaFil: Cortines, Patricio. Diagnóstico Maipú; ArgentinaFil: Carrascosa, Jorge. Diagnóstico Maipú; ArgentinaFil: Parodi, Juan C.. Sanatorio Trinidad; Argentin

Molybdenum sputtering film characterization for high gradient accelerating structures

Technological advancements are strongly required to fulfill the demands of new accelerator devices with the highest accelerating gradients and operation reliability for the future colliders. To this purpose an extensive R&D regarding molybdenum coatings on copper is in progress. In this contribution we describe chemical composition, deposition quality and resistivity properties of different molybdenum coatings obtained via sputtering. The deposited films are thick metallic disorder layers with different resistivity values above and below the molibdenum dioxide reference value. Chemical and electrical properties of these sputtered coatings have been characterized by Rutherford backscattering, XANES and photoemission spectroscopy. We will also present a three cells standing wave section coated by a molybdenum layer $\sim$ 500 nm thick designed to improve the performance of X-Band accelerating systems.Comment: manuscript has been submitted and accepted by Chinese Physics C (2012

Male sterility induced by the chemical hybridizing agent clofencet on wheat, Triticum aestivum and T. turgidum var. durum

The objective of this experiment was to evaluate the male sterilizing activity induced by the chemical hybridizing agent (CHA) clofencet, on four wheat varieties: two Triticum aestivum cultivars, 'Pia' and 'Claudia', and two Triticum turgidum var. durum cultivars, 'Capri' and 'Ambra'. The CHA was sprayed at two stages of the Feekes scale, 7.5 and 8.5, using four rates of active ingredients (0, 3.5, 5.0 and 6.5 kgּ ha-1) in a split block design with fi ve replicates. The effi ciency of the treatments was determined by measuring developed seeds and calculating male sterility (MS). Results showed that MS increased with increasing dosage and was more pronounced at the latest stage of development. The MS average for the highest dosage was 47.3% in the first stage of application and reached 84% at the second stage of application. Cultivars responded differently to the CHA, but no differences clearly attributable to species could be detected. T. aestivum cultivar ‘Pia’ reached 96% MS, a value that justifi es the use of clofencet as a CHA for hybrid wheat production. The insufficient levels of MS detected in the other cultivars were due to causes not determined in this study

Applicability of a forecasting chain in a different morphological environment in Italy

International audienceThe operational meteo-hydrological forecasting chain of the Liguria Region (NW Italy) is applied to a different morphoclimatic environment, such as the Emilia Romagna Region (N Italy). Modification to the chain, both in models and in procedures, are introduced to overcome problems related to medium dimension catchments (A?1000km2), characterized by complex altimetry profiles and antropical interventions along the river. The main feature of the original operational procedure, that is the probabilistic approach, is maintained. Hydraulic hazard reduction through artificial reservoirs management is exploited with reference to a specific event occurred on the Reno basin (Emilia Romagna Region)

Improved Determination of the CKM Angle alpha from B to pi pi decays

Motivated by a recent paper that compares the results of the analysis of the CKM angle alpha in the frequentist and in the Bayesian approaches, we have reconsidered the information on the hadronic amplitudes, which helps constraining the value of alpha in the Standard Model. We find that the Bayesian method gives consistent results irrespective of the parametrisation of the hadronic amplitudes and that the results of the frequentist and Bayesian approaches are equivalent when comparing meaningful probability ranges or confidence levels. We also find that from B to pi pi decays alone the 95% probability region for alpha is the interval [80^o,170^o], well consistent with recent analyses of the unitarity triangle where, by using all the available experimental and theoretical information, one gets alpha = (93 +- 4)^o. Last but not least, by using simple arguments on the hadronic matrix elements, we show that the unphysical region alpha ~ 0, present in several experimental analyses, can be eliminated.Comment: 16 pages, 7 figure

Update of the Unitarity Triangle Analysis

We present the status of the Unitarity Triangle Analysis (UTA), within the Standard Model (SM) and beyond, with experimental and theoretical inputs updated for the ICHEP 2010 conference. Within the SM, we find that the general consistency among all the constraints leaves space only to some tension (between the UTA prediction and the experimental measurement) in BR(B -> tau nu), sin(2 beta) and epsilon_K. In the UTA beyond the SM, we allow for New Physics (NP) effects in (Delta F)=2 processes. The hint of NP at the 2.9 sigma level in the B_s-\bar B_s mixing turns out to be confirmed by the present update, which includes the new D0 result on the dimuon charge asymmetry but not the new CDF measurement of phi_s, being the likelihood not yet released.Comment: 4 pages, 2 figures, Proceedings of the 35th International Conference of High Energy Physics - ICHEP2010 (July 22-28, 2010, Paris