| 1351. |
- Vasilopoulou, T., et al.
(författare)
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Improved neutron activation dosimetry for fusion
- 2019
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Ingår i: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 139, s. 109-114
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Tidskriftsartikel (refereegranskat)abstract
- Neutron activation technique has been widely used for the monitoring of neutron fluence at the Joint European Torus (JET) whereas it is foreseen to be employed at future fusion plants, such as ITER and DEMO. Neutron activation provides a robust tool for the measurement of neutron fluence in the complex environment encountered in a tokamak. However, activation experiments previously performed at JET showed that the activation foils used need to be calibrated in a real fusion environment in order to provide accurate neutron fluence data. Triggered by this challenge, an improved neutron activation method for the evaluation of neutron fluence at fusion devices has been developed. Activation assemblies similar to those used at JET were irradiated under 14 MeV neutrons at the Frascati Neutron Generator (FNG) reference neutron field. The data obtained from the calibration experiment were applied for the analysis of activation foil measurements performed during the implemented JET Deuterium-Deuterium (D-D) campaign. The activation results were compared against thermoluminescence measurements and a satisfactory agreement was observed. The proposed method provides confidence on the use of activation technique for the precise estimation of neutron fluence at fusion devices and enables its successful implementation in the forthcoming JET Deuterium-Tritium (D-T) campaign.
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| 1352. |
- Vedder, Benjamin, 1987-, et al.
(författare)
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Towards Collision Avoidance for Commodity Hardware Quadcopters with Ultrasound Localization
- 2015
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Ingår i: 2015 International Conference on Unmanned Aircraft Systems (ICUAS). - [S.l.] : IEEE. - 9781479960095 - 9781479960101 ; , s. 193-203
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Konferensbidrag (refereegranskat)abstract
- We present a quadcopter platform built with commodity hardware that is able to do localization in GNSS-denied areas and avoid collisions by using a novel easy-to-setup and inexpensive ultrasound-localization system. We address the challenge to accurately estimate the copter's position and not hit any obstacles, including other, moving, quadcopters. The quadcopters avoid collisions by placing contours that represent risk around static and dynamic objects and acting if the risk contours overlap with ones own comfort zone. Position and velocity information is communicated between the copters to make them aware of each other. The shape and size of the risk contours are continuously updated based on the relative speed and distance to the obstacles and the current estimated localization accuracy. Thus, the collision-avoidance system is autonomous and only interferes with human or machine control of the quadcopter if the situation is hazardous. In the development of this platform we used our own simulation system using fault-injection (sensor faults, communication faults) together with automatically-generated tests to identify problematic scenarios for which the localization and risk contour parameters had to be adjusted. In the end, we were able to run thousands of simulations without any collisions, giving us confidence that also many real quadcopters can manoeuvre collision free in space-constrained GNSS-denied areas. ©2015 IEEE.
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| 1353. |
- Vega, J., et al.
(författare)
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Real-time implementation with FPGA-based DAQ system of a probabilistic disruption predictor from scratch
- 2018
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Ingår i: Fusion engineering and design. - : Elsevier BV. - 0920-3796 .- 1873-7196. ; 129, s. 179-182
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Tidskriftsartikel (refereegranskat)abstract
- Real-time (RT) disruption prediction (DP) is essential to trigger mitigation actions that avoid irreversible damage to the devices. This paper deals with disruption mitigation alarms and performs the RT implementation of a probabilistic predictor. The RT implementation has been carried out with a fast controller with DAQ FPGA-based data acquisition devices corresponding to ITER catalogue (in particular, a reconfigurable Input/Output platform has been used). Up to three input signals have been used and relevant information for the prediction is extracted from the temporal and the frequency domains. The signals are read from the JET database. Then D/A conversions are carried out and used as inputs to the real time system. In this way, the whole process of digitization, data analysis and prediction is performed. The computation time for each prediction takes less than 200 mu s.
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| 1354. |
- Verma, Deepti, et al.
(författare)
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The Q705K polymorphism in NLRP3 is a gain-of-function alteration leading to excessive interleukin-1β and IL-18 production
- 2012
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Ingår i: PLOS ONE. - San Fransisco, USA : Public Library of Science. - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Q705K polymorphism in NLRP3 has been implicated in several chronic inflammatory diseases. In this study, we determine the functional role of this commonly occurring polymorphism using an in-vitro system.Methods / Principle findings: NLRP3-WT and NLRP3-Q705K were retrovirally transduced into the human monocytic cell line THP-1, followed by the assessment of IL-1β and IL-18 levels in the cell culture supernatant. THP-1 cells expressing the above NLRP3 variants were sorted based upon Green Fluorescent Protein (GFP) expression. Cytokine response to alum (one of the most widely used adjuvants in vaccines) in the cells stably expressing NLRP3-WT and NLRP3-Q705K were determined. IL-1β and IL-18 levels were found to be elevated in THP-1 cells transduced with NLRP3-Q705K compared to the NLRP3-WT. Upon exposure to alum, THP-1 cells stably expressing NLRP3-Q705K displayed an increased production of IL-1β, IL-18 and TNF-α, in a caspase-1 and IL-1 receptor-dependent manner.Conclusions: Collectively, these findings show that the Q705K polymorphism in NLRP3 is a gain-of-function alteration leading to an overactive NLRP3 inflammasome. The option of IL-1β blockade may be considered in patients with chronic inflammatory disorders that are unresponsive to conventional treatments.
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| 1355. |
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| 1356. |
- Viberg, Henrik, et al.
(författare)
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Adult dose-dependent behavioral and cognitive disturbances after a single neonatal PFHxS dose
- 2013
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Ingår i: Toxicology. - : Elsevier BV. - 0300-483X .- 1879-3185. ; 303, s. 185-191
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Tidskriftsartikel (refereegranskat)abstract
- Perfluoroalkyl acids, including perfluorohexane sulfonate (PFHxS), are fluorinated organic compounds used as surfactants and water and stain repellents in carpets, paper, and textiles, with characteristics to bioaccumulate and biomagnify in the food chain. PFHxS is found in umbilical cord blood, human milk and child serum from all over the world. We have recently reported that neonatal exposure to certain perfluoroalkyl acids, PFOS and PFOA, can induce persistent aberrations in spontaneous behavior and also affect learning and memory functions in the adult animal. The present study indicates that a single exposure to PFHxS on postnatal day 10, during a vulnerable period of brain development can alter adult spontaneous behavior and cognitive function in both male and female mice, effects that are both dose-response related and long-lasting/irreversible. PFHxS affected the cholinergic system, manifested as altered nicotine-induced behavior in adult animals. This is also in agreement with earlier studies on neonatal exposure to PFOS and PFOA. The present findings show that PFHxS, a member of the perfluoroalkyl acid group, can act as a developmental neurotoxicant and affect the cholinergic system and cognitive function and the effects show similarities with effects earlier reported after neonatal exposure to other POPs, such as bisphenol A, PBDEs and PCBs.
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| 1357. |
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| 1358. |
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| 1359. |
- Viberg, Henrik, et al.
(författare)
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Changes in spontaneous behaviour and altered response to nicotine in the adult rat, after neonatal exposure to the brominated flame retardant, decabrominated diphenyl ether (PBDE 209)
- 2007
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Ingår i: Neurotoxicology. - : Elsevier BV. - 0161-813X .- 1872-9711. ; 28:1, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs), which are used as flame retardants, have recently been shown to increase in the environment and in human milk, which is also true for the decabrominated congener, 2,2′,3,3′,4,4′,5,5′,6,6′-decaBDE (PBDE 209). We have recently reported that neonatal exposure to PBDE 209 can induce persistent aberrations in spontaneous behaviour, in mice, effects that get worse with age. Other PBDE congeners affect learning and memory functions and the cholinergic system in adult mice and rats. The present study indicates that spontaneous behaviour, along with the cholinergic system during its developing stage, can be targets for PBDE 209 in the rat. Neonatal oral exposure of male Sprague–Dawley rats, on postnatal day 3, to 6.7, and 20.1 mg PBDE 209/kg body weight, was shown to disrupt normal spontaneous behaviour at 2 months of age. Also, rats exposed to the high dose of PBDE 209 showed a different response to adult nicotine treatment, compared to control rats. These findings show similarities to observations made from neonatal exposure of rats or mice to 2,2′,4,4′,5-pentaBDE (PBDE 99), 2,2′,4,4′,5,5′-hexaBDE (PBDE 153) and certain PCBs, compounds shown to affect both spontaneous behaviour and the cholinergic system. It is also clear from the present study and from recent studies from our research group that both lower and higher brominated diphenyl ethers can cause similar developmental neurotoxic effects in both mice and rats.
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| 1360. |
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