Contribution to fusion research from IAEA coordinated research projects and joint experiments

The paper presents objectives and activities of IAEA Coordinated Research Projects 'Conceptual development of steady-state compact fusion neutron sources' and 'Utilisation of a network of small magnetic confinement fusion devices for mainstream fusion research'. The background and main projects of the CRP on FNS are described in detail, as this is a new activity at IAEA. Recent activities of the second CRP, which continues activities of previous CRPs, are overviewed

Observation of secondary instability of 2/1 magnetic island in compass high density limit plasmas

Density limit disruptions (DLDs) have been observed in tokamak plasmas when high density regimes are explored. The DLDs are harmless in small size tokamaks like COMPASS,larger tokamaks like JET try to avoid them and they are extremely undesirable in ITER sizetokamaks due to the severe structural damages they can cause. It is very important to understand the dynamics of the DLDs so that better strategies to ameliorate or avoid them can bedeveloped. In this work, following detection in JET [1] of a secondary instability (SI) to thewell-known m/n = 2/1 MHD mode (where m and n are the poloidal and toroidal mode numbers, respectively) in the precursor of DLD, we analyse the evolution of the 2/1 magnetic islandin COMPASS DLD to look for the presence of this SI just close to the onset of energy quenchphase of the disruption. The presence of this SI to the magnetic island was associated with theoccurrence of minor disruptions preceding the major disruption and with the major disruptionitself in [1]. The coherence observed between the perturbations caused by the SI in the magneticpoloidal flux and in the electron temperature was very high (above 0.9), allowing to determinethat the SI perturbations came from the same position as the magnetic island. In the work presented here, only the perturbations in the magnetic poloidal flux are analysed since at the time ofthe experiments in COMPASS, no diagnostics was operational for measuring the time evolutionof the electron temperature with high time rate.Nonlinear MHD numerical simulations have also shown that island deformation during itsrapid growth can lead to the secondary magnetic island formation [2]. A recent review [3] ofthe theory of current sheet formation that leads to magnetic reconnection discusses the role ofplasmoids during magnetic island evolution. Since the validity ranges of the mentioned theoretical works are not directly comparable to the experimental conditions, one cannot claimwith certainty that the SI observed in JET [1] and in COMPASS disruptions (reported here)are the same as observed in those numerical works [2, 3]. However, there are some qualitative43rd EPS Conference on Plasma Physics P5.003similarities between them.The main COMPASS [4] diagnostics used for the analysis in the present work, are the threetoroidally separated arrays (A at 32.5◦, B at 212.5◦and C at 257.5◦from the vessel axis) ofMirnov coils (MCs), each with 24 MCs located poloidally. The MC arrays A and C, toroidallyseparated by 135◦, measure the change in poloidal magnetic flux, dBp/dt. The MC array B,toroidally separated by 180◦to the array A, measures the poloidal magnetic field, Bp. Thesemagnetic sensors have good responsivity to high frequency (up to 1 MHz)

Is the grass greener on the other side?

Facing rapidly ageing populations, many Western countries aim to stimulate informal care provision as a way to meet the growing long-term care (LTC) demand. While various studies report the impact of providing informal care on the health of caregivers, it is less clear whether and to what extent this impact differs across countries. Using propensity score matching we match caregivers to similar non-caregiving individuals using four waves of the Dutch Study on Transitions in Employment, Ability and Motivation and the UK Household Longitudinal Study. The samples consist of 8,129 Dutch and 7,186 UK respondents, among which respectively 1,711 and 1,713 individuals are identified as caregivers. We explore whether the health impact of providing informal care differs by country once similar caregivers, in terms of the intensity of provided care, are compared. In both countries we find negative mental health effects of providing informal ca

Motor learning and cross-limb transfer rely upon distinct neural adaptation processes.

Performance benefits conferred in the untrained limb after unilateral motor practice are termed cross-limb transfer. Although the effect is robust, the neural mechanisms remain incompletely understood. Here we use non-invasive brain stimulation to reveal that the neural adaptations that mediate motor learning in the trained limb are distinct from those that underlie cross-limb transfer to the opposite limb. Thirty-six participants practiced a ballistic motor task with their right index finger (150 trials), followed by intermittent-theta burst stimulation (iTBS) applied to the trained (contralateral) primary motor cortex (cM1 group), the untrained (ipsilateral) M1 (iM1 group), or the vertex (sham group). Following stimulation, another 150 training trials were undertaken. Motor performance and corticospinal excitability were assessed before motor training, pre- and post-iTBS, and following the second training bout. For all groups, training significantly increased performance and excitability of the trained hand, and performance, but not excitability, of the untrained hand, indicating transfer at the level of task performance. The typical faciltatory effect of iTBS on MEPs was reversed for cM1, suggesting homeostatic metaplasticity, and prior performance gains in the trained hand were degraded, suggesting that iTBS interfered with learning. In stark contrast, iM1 iTBS facilitated both performance and excitability for the untrained hand. Importantly, the effects of cM1 and iM1 iTBS on behaviour were exclusive to the hand contralateral to stimulation, suggesting that adaptations within the untrained M1 contribute to cross-limb transfer. However, the neural processes that mediate learning in the trained hemisphere versus transfer in the untrained hemisphere appear distinct

Dynamic proteomic profiling of a unicellular cyanobacterium Cyanothece ATCC51142 across light-dark diurnal cycles

<p>Abstract</p> <p>Background</p> <p>Unicellular cyanobacteria of the genus <it>Cyanothece </it>are recognized for their ability to execute nitrogen (N₂)-fixation in the dark and photosynthesis in the light. An understanding of these mechanistic processes in an integrated systems context should provide insights into how <it>Cyanothece </it>might be optimized for specialized environments and/or industrial purposes. Systems-wide dynamic proteomic profiling with mass spectrometry (MS) analysis should reveal fundamental insights into the control and regulation of these functions.</p> <p>Results</p> <p>To expand upon the current knowledge of protein expression patterns in <it>Cyanothece </it>ATCC51142, we performed quantitative proteomic analysis using partial ("unsaturated") metabolic labeling and high mass accuracy LC-MS analysis. This dynamic proteomic profiling identified 721 actively synthesized proteins with significant temporal changes in expression throughout the light-dark cycles, of which 425 proteins matched with previously characterized cycling transcripts. The remaining 296 proteins contained a cluster of proteins uniquely involved in DNA replication and repair, protein degradation, tRNA synthesis and modification, transport and binding, and regulatory functions. Functional classification of labeled proteins suggested that proteins involved in respiration and glycogen metabolism showed increased expression in the dark cycle together with nitrogenase, suggesting that N₂-fixation is mediated by higher respiration and glycogen metabolism. Results indicated that <it>Cyanothece </it>ATCC51142 might utilize alternative pathways for carbon (C) and nitrogen (N) acquisition, particularly, aspartic acid and glutamate as substrates of C and N, respectively. Utilization of phosphoketolase (PHK) pathway for the conversion of xylulose-5P to pyruvate and acetyl-P likely constitutes an alternative strategy to compensate higher ATP and NADPH demand.</p> <p>Conclusion</p> <p>This study provides a deeper systems level insight into how <it>Cyanothece </it>ATCC51142 modulates cellular functions to accommodate photosynthesis and N₂-fixation within the single cell.</p

In vivo biomolecular imaging of zebrafish embryos using confocal Raman spectroscopy

Zebrafish embryos provide a unique opportunity to visualize complex biological processes, yet conventional imaging modalities are unable to access intricate biomolecular information without compromising the integrity of the embryos. Here, we report the use of confocal Raman spectroscopic imaging for the visualization and multivariate analysis of biomolecular information extracted from unlabeled zebrafish embryos. We outline broad applications of this method in: (i) visualizing the biomolecular distribution of whole embryos in three dimensions, (ii) resolving anatomical features at subcellular spatial resolution, (iii) biomolecular profiling and discrimination of wild type and ΔRD1 mutant Mycobacterium marinum strains in a zebrafish embryo model of tuberculosis and (iv) in vivo temporal monitoring of the wound response in living zebrafish embryos. Overall, this study demonstrates the application of confocal Raman spectroscopic imaging for the comparative bimolecular analysis of fully intact and living zebrafish embryos

How metaphysical commitments shape the study of psychological mechanisms

The study of psychological mechanisms is an interdisciplinary endeavour, requiring insights from many different domains (from electrophysiology, to psychology, to theoretical neuroscience, to computer science). In this article, I argue that philosophy plays an essential role in this interdisciplinary project, and that effective scientific study of psychological mechanisms requires that working scientists be responsible metaphysicians. This means adopting deliberate metaphysical positions when studying mechanisms that go beyond what is empirically justified regarding the nature of the phenomenon being studied, the conditions of its occurrence, and its boundaries. Such metaphysical commitments are necessary in order to set up experimental protocols, determine which variables to manipulate under experimental conditions, and which conclusions to draw from different scientific models and theories. It is important for scientists to be aware of the metaphysical commitments they adopt, since they can easily be led astray if invoked carelessly

BALL - biochemical algorithms library 1.3

<p>Abstract</p> <p>Background</p> <p>The Biochemical Algorithms Library (BALL) is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements.</p> <p>Results</p> <p>Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics.</p> <p>Conclusions</p> <p>BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL). Parts of the code are distributed under the GNU Public License (GPL). BALL is available as source code and binary packages from the project web site at <url>http://www.ball-project.org</url>. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.</p