Pencil beam characteristics of the next-generation proton scanning gantry of PSI: design issues and initial commissioning results

In this paper we report on the main design features, on the realization process and on selected first results of the initial commissioning of the new Gantry 2 of PSI for the delivery of proton therapy with new advanced pencil beam scanning techniques. We present briefly the characteristics of the new gantry system with main emphasis on the beam optics, on the characterization of the pencil beam used for scanning and on the performance of the scanning system. The idea is to give an overview of the major components of the whole system. The main long-term technical goal of the new equipment of Gantry 2 is to expand the use of pencil beam scanning to the whole spectrum of clinical indications including moving targets. We report here on the initial experience and problems encountered in the development of the system with selected preliminary results of the ongoing commissioning of Gantry

Effect of the change of social environment on the behavior of a captive brown bear (Ursus arctos)

We observed the behavior of a captive sterilized male brown bear before and after the death of his female sibling to investigate the effect of the change of social environment on his behavior and welfare. Observations were carried out by continuous recording during daylight for 6 wk prior to hibernation when the bear was kept with the sibling, and they were repeated 2 years later when the bear was alone (total observation time is 108 h). Feeding, moving, and the total amount of time spent resting (including sleeping and alert inactive) were not affected by the change of social environment. However, when the bear was alone, the percentage of time he spent alert inactive almost trebled (pair, 17.7 \ub1 3.3%; alone, 48.5 \ub1 5.5%; P < 0.001), and the time spent sleeping was less than one-third (pair, 51.1 \ub1 6.1%; alone, 14.2 \ub1 5.0%; P < 0.001) than when the female was present. The bear spent most of his sleeping time in lateral lying posture (a posture probably associated with rapid eyes movement sleep). The percentage of time dedicated to this posture was significantly reduced after the death of his sibling (pair, 35.9 \ub1 7.4%; alone, 15.0 \ub1 5.4%; P < 0.05), whereas the percentage of time spent in quadrupedal posture increased (pair, 17.1 \ub1 5.4%; alone, 37.8 \ub1 7.8; P < 0.05). One of the possible reasons for these changes may be an increased risk perception of the bear after the death of his sibling. Our results highlight the importance of social environment and of its changes, which should be carefully considered to maintain captive bears in good welfare conditions

Validation of a high performance liquid chromatographic method for quantitative determination of boldine in fluid extract of boldo

A simple and specific method was validated for quantification of boldine in fluid extract of boldo (Peumus boldus Mol.) using high-performance liquid chromatography. A reversed-phase C18 , Phenomenex® (150 x 4.6 mm, 4 µm) column was employed. The mobile phase consisted of 0.1 % trifluoroacetic acid and acetonitrile (78:22, v/v) at a flow rate of 0.8 mL/min. The column was maintained at 30 °C and the boldine peak detection was performed at a wavelength of 281 nm. The parameters used in the validation process were: linearity, specificity, precision, accuracy, limit of detection, limit of quantification and robustness. The validated method was selective and linear (r≥0.9991) for boldine concentration considering 5.0, 10.0, 15.0, 20.0 and 25.0 micro;g/mL. The recovery ranged from 90.93 % to 96.24 % and the limit of quantification was 2.41 micro;g/mL. The precision determined was reported as RSD (1.73 %). The method can be successfully applied to measure boldine concentrations in Boldo extract and be included in routine analysis of quality control.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Validation of a high performance liquid chromatographic method for quantitative determination of boldine in fluid extract of boldo

A simple and specific method was validated for quantification of boldine in fluid extract of boldo (Peumus boldus Mol.) using high-performance liquid chromatography. A reversed-phase C18 , Phenomenex® (150 x 4.6 mm, 4 µm) column was employed. The mobile phase consisted of 0.1 % trifluoroacetic acid and acetonitrile (78:22, v/v) at a flow rate of 0.8 mL/min. The column was maintained at 30 °C and the boldine peak detection was performed at a wavelength of 281 nm. The parameters used in the validation process were: linearity, specificity, precision, accuracy, limit of detection, limit of quantification and robustness. The validated method was selective and linear (r≥0.9991) for boldine concentration considering 5.0, 10.0, 15.0, 20.0 and 25.0 micro;g/mL. The recovery ranged from 90.93 % to 96.24 % and the limit of quantification was 2.41 micro;g/mL. The precision determined was reported as RSD (1.73 %). The method can be successfully applied to measure boldine concentrations in Boldo extract and be included in routine analysis of quality control.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Functional safety assessment of a liquid metal divertor for the European demo tokamak

A reliable strategy for the heat exhaust problem for fusion reactors is among the milestones indicated in EUROfusion (2018). In a fusion reactor, the divertor targets are subject to extremely large heat and particle fluxes. For fusion to be economically feasible, these conditions must be withstood without damage for long time. The “baseline” strategy will be employed for the ITER experiment (which is being built in France) and is based on actively cooled tungsten monoblocks. It is unclear whether this strategy will extrapolate to a future fusion reactor (such as the EU-DEMO, whose pre-conceptual design is ongoing within the EUROfusion consortium). For this reason, alternative solutions are under study, which will eventually be tested in a dedicated experiment in Italy, namely the Divertor Tokamak Test (DTT). One possibility is to employ liquid metal divertors (LMDs), for which the plasma-facing surface is inherently self-healing and immune to thermo-mechanical stresses. Within the framework of the pre-conceptual design of an LMD for the EU-DEMO, safety issues need to be considered at an early stage. In this work we present a preliminary but systematic safety analysis for this system, by means of the Functional Failure Mode and Effect Analysis (FFMEA). The FFMEA allows to identify possible accident initiators for systems undergoing pre-conceptual design, when more specific safety evaluations (e.g. at the component level) are not possible, US Nuclear Regulatory Commission (2009). This is done by postulating the loss of a system function rather than a specific component failure, thus compensating for the lack of detailed design information. For each function, the potential causes of its loss, a plausible evolution and preventive and mitigative measures are investigated, possibly specifying the need for further information. The initiating events are grouped according to consequences and the plant response. For each group, the Postulated Initiating Event (PIE) is chosen. The PIEs list drives and limits the set of accidental scenarios which will undergo deterministic analysis in a successive phase of the work, in order to evaluate the capacity of the system to withstand/mitigate its consequences. This will assess whether safety limits are respected or whether additional safety provisions are required. From the PIEs list, the design basis accident (DBA) and beyond design basis accident (BDBA) will eventually be selected

Isospin Splitting in the Baryon Octet and Decuplet

Baryon mass splittings are analyzed in terms of a simple model with general pairwise interactions. At present, the $\Delta$ masses are poorly known from experiments. Improvement of these data would provide an opportunity to make a significant test of our understanding of electromagnetic and quark-mass contributions to hadronic masses. The problem of determining resonance masses from scattering and production data is discussed.Comment: 9 pages, LATEX inc. 2 LATEX "pictures", CMU-HEP91-24-R9

Functioning conditions of the Casale pumping station in Mantova, Italy

Abstract. Pump speed, input power, pressure and discharge data are analyzed for evaluating functioning conditions of Casale pumping station in Mantova, Italy, managed by TeaAcque. A model based on the affinity laws is used to simulate the behavior of the installed variable speed pumps. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves allow predicting the efficiency when the functioning conditions change. The relationship between the rotation speed and the efficiency is also derived

Involutive orbits of non-Noether symmetry groups

We consider set of functions on Poisson manifold related by continues one-parameter group of transformations. Class of vector fields that produce involutive families of functions is investigated and relationship between these vector fields and non-Noether symmetries of Hamiltonian dynamical systems is outlined. Theory is illustrated with sample models: modified Boussinesq system and Broer-Kaup system.Comment: LaTeX 2e, 10 pages, no figure

A Computational Understanding of Inter-Individual Variability in CYP2D6 Activity to Investigate the Impact of Missense Mutations on Ochratoxin A Metabolism

Cytochrome P-450 (CYP) enzymes have a key role in the metabolism of xenobiotics of food origin, and their highly polymorphic nature concurs with the diverse inter-individual variability in the toxicokinetics (TK) and toxicodynamics (TD) of food chemicals. Ochratoxin A is a well-known mycotoxin which contaminates a large variety of food and is associated with food safety concerns. It is a minor substrate of CYP2D6, although the effects of CYP2D6 polymorphisms on its metabolism may be overlooked. Insights on this aspect would provide a useful mechanistic basis for a more science-based hazard assessment, particularly to integrate inter-individual differences in CYP2D6 metabolism. This work presents a molecular modelling approach for the analysis of mechanistic features with regard to the metabolic capacity of CYP2D6 variants to oxidise a number of substrates. The outcomes highlighted that a low-frequency CYP2D6 variant (CYP2D6*110) is likely to enhance ochratoxin A oxidation with possible consequences on TK and TD. It is therefore recommended to further analyse such TK and TD consequences. Generally speaking, we propose the identification of mechanistic features and parameters that could provide a semi-quantitative means to discriminate ligands based on the likelihood to undergo transformation by CYP2D6 variants. This would support the development of a fit-for-purpose pipeline which can be extended to a tool allowing for the bulk analysis of a large number of compounds. Such a tool would ultimately include inter-phenotypic differences of polymorphic xenobiotic-metabolising enzymes in the hazard assessment and risk characterisation of food chemicals