Requirements and modelling of fast particle injection in RFX-mod tokamak plasmas

The planned upgrade of the RFX-mod device is a good opportunity to widen the operational space of the machine, in both RFP and tokamak configurations. Installation of a power neutral beam injector is also envisaged and a NB system compatible with RFX-mod, formerly installed in TPE-RX, is already available on site. In this work, the METIS simulator is used to study the feasibility of TPE-RX injector integration in RFX-mod circular tokamak plasmas. METIS code allows the simulation of a full tokamak discharge, with the addition of the neutral beam injection (NBI) which, in METIS, is described by a decay equation applied in a simplified geometry and an analytical solution of the Fokker\u2013Planck equation. In this work, RFX-mod scenarios with NBI have been studied, with careful attention to the beam absorption and plasma response to the additional heating

Neutral beam fast particle physics in fusion plasma integrated scenarios

Neutral beam injection heating is one of the most reliable ways to heat a plasma up to the temperatures needed to achieve steady-state thermonuclear fusion. This system injects neutral particles with energy much higher than the bulk ion energy, introducing a population of energetic particles which collide with the plasma ions and electrons. In this way energy and momen- tum are transferred to the plasma giving as final result an increase of the tar- get plasma temperature and, depending on the beam characteristics, possible modifications of its flow and current profile. Numerical modelling of the behaviour of fast particles in tokamak plasma is the subject of this thesis. Analytical and Monte Carlo models have been applied to different devices (RFX-mod, JT-60 SA and TCV) in order to study the impact of these particles in both inductive (standard) and non-inductive (advanced) scenarios. Comparison between the different codes have been made in order to assess if the different models apply correctly to the cases studied. RFX-mod device is under modification and the installation of a neutral beam injector (with fixed parameters and geometry) is in the upgrade hy- pothesis. The impact of energetic particles in RFX-mod tokamak plasmas is discussed in this work using METIS fast tokamak simulator and compared with NUBEAM Monte Carlo code. The impact of energetic particles in JT-60 SA superconducting tokamak is studied with ASCOT Monte Carlo orbit solver. This device relies on a wide and flexible set of beams for plasma heating and current drive, both for stan- dard and advanced scenarios. The behaviour of the fast particles in JT-60 SA standard and advanced tokamak plasmas is analysed, showing the reliability of the neutral beam system in this device. Neutral beam injection heating in TCV is the last topic studied in this thesis. The impact of electron cyclotron wave injection heating on energetic particles behaviour has been studied in advanced tokamak scenarios, where the expected performances are not achieved using the combination of the two heating systems. Comparison between ASCOT and NUBEAM code is performed in order to check which of the two code

Bisecting Real and Fake Body Parts: Effects of Prism Adaptation After Right Brain Damage

The representation of body parts holds a special status in the brain, due to their prototypical shape and the contribution of multisensory (visual and somatosensory-proprioceptive) information. In a previous study (Sposito et al., 2010), we showed that patients with left unilateral spatial neglect exhibit a rightward bias in setting the midpoint of their left forearm, which becomes larger when bisecting a cylindrical object comparable in size. This body part advantage, found also in control participants, suggests partly different processes for computing the extent of body parts and objects. In this study we tested 16 right-brain-damaged patients, and 10 unimpaired participants, on a manual bisection task of their own (real) left forearm, or a size-matched fake forearm. We then explored the effects of adaptation to rightward displacing prism exposure, which brings about leftward aftereffects. We found that all participants showed prism adaptation (PA) and aftereffects, with right-brain-damaged patients exhibiting a reduction of the rightward bias for both real and fake forearm, with no overall differences between them. Second, correlation analyses highlighted the role of visual and proprioceptive information for the metrics of body parts. Third, single-patient analyses showed dissociations between real and fake forearm bisections, and the effects of PA, as well as a more frequent impairment with fake body parts. In sum, the rightward bias shown by right-brain-damaged patients in bisecting body parts is reduced by prism exposure, as other components of the neglect syndrome; discrete spatial representations for real and fake body parts, for which visual and proprioceptive codes play different roles, are likely to exist. Multisensory information seems to render self bodily segments more resistant to the disruption brought about by right-hemisphere injury

Sharing Social Touch in the Primary Somatosensory Cortex

SummaryTouch has an emotional and communicative meaning, and it plays a crucial role in social perception and empathy. The intuitive link between others’ somatosensations and our sense of touch becomes ostensible in mirror-touch synesthesia, a condition in which the view of a touch on another person’s body elicits conscious tactile sensations on the observer’s own body [1]. This peculiar phenomenon may implicate normal social mirror mechanisms [2]. Here, we show that mirror-touch interference effects, synesthesia-like sensations, and even phantom touches can be induced in nonsynesthetes by priming the primary somatosensory cortex (SI) directly or indirectly via the posterior parietal cortex. These results were obtained by means of facilitatory paired-pulse transcranial magnetic stimulation (ppTMS) contingent upon the observation of touch. For these vicarious effects, the SI is engaged at 150 ms from the onset of the visual touch. Intriguingly, individual differences in empathic abilities, assessed with the Interpersonal Reactivity Index [3], drive the activity of the SI when nonsynesthetes witness others’ tactile sensations. This evidence implies that, under normal conditions, touch observation activates the SI below the threshold for perceptual awareness [4]; through the visual-dependent tuning of SI activity by ppTMS, what is seen becomes felt, namely, mirror-touch synesthesia. On a broader perspective, the visual responsivity of the SI may allow an automatic and unconscious transference of the sensation that another person is experiencing onto oneself, and, in turn, the empathic sharing of somatosensations [2]

GLI ASPETTI DI DIRITTO INTERNAZIONALE PRIVATO E PROCESSUALE DEL FALLIMENTO DI GRUPPI BANCARI MULTINAZIONALI

In the absence of an international agreement among states, insolvencies of multinational groups of banks could in principle be dealt with only according to a so called \u201cterritorial approach\u201d. Under the latter, every bank of a given group is considered to be an independent entity with the consequence that several insolvency proceedings are opened with respect to each of them in any of the states of their seats, different laws are applied and every court will try to grab as much assets as it can in order to satisfy its own local creditors. The five multinational banking defaults occurred in the last thirty years (BCCI, Fortis, Dexia, Kaupthing and Lehman Brothers) had to deal with such a scenario. Fortis, Dexia and Kaupthing had been resolved through a territorial approach. On the contrary, liquidators and courts involved in the BCCI and Lehman insolvencies (respectively begun in 1991 and 2008) tried to overcome the massive inconveniences that would have derived from a piecemeal liquidation by voluntarily cooperating and coordinating the proceedings, through \u201ccross-border insolvency agreements\u201d (also called \u201cprotocols\u201d). Inspiration came from a more consolidated experience matured in this same direction in the corporate groups insolvencies. Awareness has then arisen - stronger than before - among states, practitioners and academics, of the need to regulate these insolvencies ex ante and once for all, in order to avoid the uncertainties of a case-by-case solution. Quite a few international organizations, such as the EU, the IMF, the Basel Committee and the Financial Stability Board, have been and still are pursuing this aim by preparing a considerable number of either soft law or hard law instruments for adoption by states

ON THE ASSIMILATION OF GNSS PWV MEASUREMENTS IN HEAVY TO TORRENTIAL RAIN EVENTS IN DAVAO CITY, PHILIPPINES

A standalone Global Navigation Satellite System (GNSS) receiver was utilized in this study to get a measure of the atmospheric water vapor in Davao City, Philippines. It aims to monitor the variability of GNSS precipitable water vapor (PWV) especially during heavy to torrential rain. The results of the study showed a positive correlation between GNSS-PWV and precipitation especially in these severe (heavy to torrential) rain events which implies that the assimilation of atmospheric water vapor measurements can improve forecasts of such events

Dopamine inhibits cytosolic Ca2+ increases in rat lactotroph cells. Evidence of a dual mechanism of action.

Single rat lactotroph cells were studied after loading with the cytosolic free Ca2+ concentration ([Ca2+]i) indicator fura-2 either 1 or 3 days after cell dispersion. Under unstimulated conditions, two groups of lactotrophs were observed, the first (predominant at day 1) with large [Ca2+]i fluctuations (peaks up to 300 nM) probably due to spontaneous action potentials and the second (predominant at 3 days) with stable [Ca2+]i (values variable between 65 and 200 nM). The effect of dopamine on the resting [Ca2+]i was different in the two groups. Even at high dopamine concentrations, no change occurred in the second group; whereas in the first, disappearance of fluctuations and marked decrease of [Ca2+]i were observed. These effects of dopamine appear to be due to hyperpolarization that was demonstrated by the use of a specific fluorescent indicator, bis(oxonol). Two types of triggered [Ca2+]i transients were studied in detail: those due to redistribution of Ca2+ from the intracellular stores (induced by thyrotropin-releasing hormone) and those due to Ca2+ influx through voltage-gated Ca2+ channels (induced by high [K+]). Dopamine (1 microM) markedly inhibited both these transients by the action of D2 receptors (blocked by 1-sulpiride and domperidone). All effects of dopamine were prevented by treatment of the cells with pertussis toxin, indicating the involvement of one (or more) GTP-binding protein(s). Another consequence of D2 receptor activation is the inhibition of adenylate cyclase. Treatments (cholera toxin, forskolin), known to raise cAMP levels, were found to dissociate the effects of dopamine on [Ca2+]i inasmuch as they markedly relieved the inhibition of the redistributive transients by thyrotropin-releasing hormone but left hyperpolarization and inhibition of K+ transients unaffected. The spectrum of intracellular signals elicited by the activation of D2 receptors is therefore complex and includes at least two mechanisms that involve [Ca2+]i, one related and the other independent of the decrease of cAMP levels

Advanced spot quality analysis in two-colour microarray experiments

Background: Image analysis of microarrays and, in particular, spot quantification and spot quality control, is one of the most important steps in statistical analysis of microarray data. Recent methods of spot quality control are still in early age of development, often leading to underestimation of true positive microarray features and, consequently, to loss of important biological information. Therefore, improving and standardizing the statistical approaches of spot quality control are essential to facilitate the overall analysis of microarray data and subsequent extraction of biological information. Findings: We evaluated the performance of two image analysis packages MAIA and GenePix (GP) using two complementary experimental approaches with a focus on the statistical analysis of spot quality factors. First, we developed control microarrays with a priori known fluorescence ratios to verify the accuracy and precision of the ratio estimation of signal intensities. Next, we developed advanced semi-automatic protocols of spot quality evaluation in MAIA and GP and compared their performance with available facilities of spot quantitative filtering in GP. We evaluated these algorithms for standardised spot quality analysis in a whole-genome microarray experiment assessing well-characterised transcriptional modifications induced by the transcription regulator SNAI1. Using a set of RT-PCR or qRT-PCR validated microarray data, we found that the semi-automatic protocol of spot quality control we developed with MAIA allowed recovering approximately 13% more spots and 38% more differentially expressed genes (at FDR = 5%) than GP with default spot filtering conditions. Conclusion: Careful control of spot quality characteristics with advanced spot quality evaluation can significantly increase the amount of confident and accurate data resulting in more meaningful biological conclusions. © 2008 Friederich et al; licensee BioMed Central Ltd

How to get by with half a loop - An investigation of visual and auditory codes in a case of impaired phonological short-term memory (pSTM).

In the field of cognitive neuropsychology of phonological short-term memory (pSTM), a key debate surrounds the issue of how impairment on tasks deemed to tap this system imply a dissociable phonological input and output buffer system, with the implication that impairments can be fractionated across disruption to separate functional components (Nickels, Howard & Best, 1997). This study presents CT, a conduction aphasic who showed no impairment on basic auditory discrimination tasks, but had very poor nonword repetition. Clear-cut examples of such cases are very rare (see Jacquemot, Dupoux & Bachoud-Levi, 2007), and we interpret the case with reference to a pSTM model that includes input and output buffers. The dissociation between performance on auditory phonological tasks and visual phonological tasks we interpret as consistent with disruption to the link from input buffer to output buffer without concurrent damage to connections from output to input. Previous research has also shown that patients with impairments of pSTM can make visual confusions with orthographically presented items in tasks seeking to tap this mechanism (Warrington & Shallice, 1972), which might stem from having an incomplete pSTM loop. In light of this we examined whether CT's ability on tests of ISR was affected by visual orthographic similarity among list items, and this is indeed what we observed. On balance then, CT's overall profile is considered best interpreted with respect to a dual buffer pSTM model (e.g., Vallar & Papagno, 2002). [Abstract copyright: Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.