Negative-energy perturbations in cylindrical equilibria with a radial electric field

The impact of an equilibrium radial electric field $E$ on negative-energy perturbations (NEPs) (which are potentially dangerous because they can lead to either linear or nonlinear explosive instabilities) in cylindrical equilibria of magnetically confined plasmas is investigated within the framework of Maxwell-drift kinetic theory. It turns out that for wave vectors with a non-vanishing component parallel to the magnetic field the conditions for the existence of NEPs in equilibria with E=0 [G. N. Throumoulopoulos and D. Pfirsch, Phys. Rev. E 53, 2767 (1996)] remain valid, while the condition for the existence of perpendicular NEPs, which are found to be the most important perturbations, is modified. For $|e_i\phi|\approx T_i$ ($\phi$ is the electrostatic potential) and $T_i/T_e > \beta_c\approx P/(B^2/8\pi)$ ($P$ is the total plasma pressure), a case which is of operational interest in magnetic confinement systems, the existence of perpendicular NEPs depends on $e_\nu E$, where $e_\nu$ is the charge of the particle species $\nu$. In this case the electric field can reduce the NEPs activity in the edge region of tokamaklike and stellaratorlike equilibria with identical parabolic pressure profiles, the reduction of electron NEPs being more pronounced than that of ion NEPs.Comment: 30 pages, late

New generation of hydraulic pedotransfer functions for Europe

A range of continental-scale soil datasets exists in Europe with different spatial representation and based on different principles. We developed comprehensive pedotransfer functions (PTFs) for applications principally on spatial datasets with continental coverage. The PTF development included the prediction of soil water retention at various matric potentials and prediction of parameters to characterize soil moisture retention and the hydraulic conductivity curve (MRC and HCC) of European soils. We developed PTFs with a hierarchical approach, determined by the input requirements. The PTFs were derived by using three statistical methods: (i) linear regression where there were quantitative input variables, (ii) a regression tree for qualitative, quantitative and mixed types of information and (iii) mean statistics of developer-defined soil groups (class PTF) when only qualitative input parameters were available. Data of the recently established European Hydropedological Data Inventory (EU-HYDI), which holds the most comprehensive geographical and thematic coverage of hydro-pedological data in Europe, were used to train and test the PTFs. The applied modelling techniques and the EU-HYDI allowed the development of hydraulic PTFs that are more reliable and applicable for a greater variety of input parameters than those previously available for Europe. Therefore the new set of PTFs offers tailored advanced tools for a wide range of applications in the continent

New developments in ICRF antennas and non-traditional applications of HF power on TEXTOR

This paper reviews the present status of new developments in ICRF antennas, recent results on more realistic modeling of ICRF antennas using the 3-D full electromagnetic code ICANT and, finally, the latest development in the scenarios of non-traditional applications of HF power for wall conditioning

Development of ITER relevant ICRF wall conditioning technique on European tokamaks

In future reactor-scale superconducting fusion devices such as ITER, the presence of a permanent high magnetic field will prevent the use of conventional Glow Discharge Conditioning in between shots. Therefore, only discharges fully compatible with the presence of high magnetic field can be used for the conditioning procedure. ICRF discharge has a high potential to solve this problem. The paper presents a review of the new ICRF wall conditioning technique developed on limiter tokamaks TEXTOR and TORE SUPRA and the results of the first tests on the divertor tokamaks ASDEX Upgrade and JET.У майбутніх термоядерних установках зі надпровідними магнітними системами масштабу ИТЕРа присутність постійного сильного магнітного поля буде перешкоджати використанню звичайних тліючих розрядів для підготовки вакуумних стінок між розрядами. Тому тільки розряди, що працюють при сильному магнітному полі, можуть бути використані для цих цілей. ВЧ розряди в області частот ІЦР мають великий потенціал для рішення цієї проблеми. У даній роботі представлений огляд нових ВЧ ІЦРтехнік підготовки стінок, розвитих на токамаках з лімітером TEXTOR і TORE SUPRA і результати перших іспитів на токамаках з дивертором ASDEX UPGRADE іJET.В будущих термоядерных установках с сверхпроводящими магнитными системами масштаба ИТЕРа присутствие постоянного сильного магнитного поля будет препятствовать использованию обычных тлеющих разрядов для подготовки вакуумных стенок между разрядами. Поэтому только разряды, работающие при сильном магнитном поле, могут быть использованы для этих целей. ВЧ разряды в области частот ИЦР обладают большим потенциалом для решения этой проблемы. В настоящей работе представлен обзор новых ВЧ ИЦР техник подготовки стенок , развитых на токамаках с лимитером TEXTOR и TORE SUPRA и результаты первых испытаний на токамаках с дивертором ASDEX UPGRADE и JET

Land potential assessment and trend-analysis using 2000–2021 FAPAR monthly time-series at 250 m spatial resolution

The article presents results of using remote sensing images and machine learning to map and assess land potential based on time-series of potential Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) composites. Land potential here refers to the potential vegetation productivity in the hypothetical absence of short–term anthropogenic influence, such as intensive agriculture and urbanization. Knowledge on this ecological land potential could support the assessment of levels of land degradation as well as restoration potentials. Monthly aggregated FAPAR time-series of three percentiles (0.05, 0.50 and 0.95 probability) at 250 m spatial resolution were derived from the 8-day GLASS FAPAR V6 product for 2000–2021 and used to determine long-term trends in FAPAR, as well as to model potential FAPAR in the absence of human pressure. CCa 3 million training points sampled from 12,500 locations across the globe were overlaid with 68 bio-physical variables representing climate, terrain, landform, and vegetation cover, as well as several variables representing human pressure including: population count, cropland intensity, nightlights and a human footprint index. The training points were used in an ensemble machine learning model that stacks three base learners (extremely randomized trees, gradient descended trees and artificial neural network) using a linear regressor as meta-learner. The potential FAPAR was then projected by removing the impact of urbanization and intensive agriculture in the covariate layers. The results of strict cross-validation show that the global distribution of FAPAR can be explained with an R2 of 0.89, with the most important covariates being growing season length, forest cover indicator and annual precipitation. From this model, a global map of potential monthly FAPAR for the recent year (2021) was produced, and used to predict gaps in actual vs. potential FAPAR. The produced global maps of actual vs. potential FAPAR and long-term trends were each spatially matched with stable and transitional land cover classes. The assessment showed large negative FAPAR gaps (actual lower than potential) for classes: urban, needle-leave deciduous trees, and flooded shrub or herbaceous cover, while strong negative FAPAR trends were found for classes: urban, sparse vegetation and rainfed cropland. On the other hand, classes: irrigated or post-flooded cropland, tree cover mixed leaf type, and broad-leave deciduous showed largely positive trends. The framework allows land managers to assess potential land degradation from two aspects: as an actual declining trend in observed FAPAR and as a difference between actual and potential vegetation FAPAR

An Outer Membrane Receptor of Neisseria meningitidis Involved in Zinc Acquisition with Vaccine Potential

Since the concentration of free iron in the human host is low, efficient iron-acquisition mechanisms constitute important virulence factors for pathogenic bacteria. In Gram-negative bacteria, TonB-dependent outer membrane receptors are implicated in iron acquisition. It is far less clear how other metals that are also scarce in the human host are transported across the bacterial outer membrane. With the aim of identifying novel vaccine candidates, we characterized in this study a hitherto unknown receptor in Neisseria meningitidis. We demonstrate that this receptor, designated ZnuD, is produced under zinc limitation and that it is involved in the uptake of zinc. Upon immunization of mice, it was capable of inducing bactericidal antibodies and we could detect ZnuD-specific antibodies in human convalescent patient sera. ZnuD is highly conserved among N. meningitidis isolates and homologues of the protein are found in many other Gram-negative pathogens, particularly in those residing in the respiratory tract. We conclude that ZnuD constitutes a promising candidate for the development of a vaccine against meningococcal disease for which no effective universal vaccine is available. Furthermore, the results suggest that receptor-mediated zinc uptake represents a novel virulence mechanism that is particularly important for bacterial survival in the respiratory tract

The influence of different culture microenvironments on the generation of dendritic cells from non-small-cell lung cancer patients

This study extends the model developed in Williams and Seaman’s [Williams, J. J. and Seaman, A. E. (2010). Corporate Governance and Mindfulness: The Impact of Management Accounting Systems Change, The Journal of Applied Business Research, Vol. 26, No. 5, pp. 1-17] exploratory paper examining the moderating effects of management accounting systems (MAS) change on the corporate governance/mindfulness relationship for a Canadian sample of 124 top-level accounting professionals. Canonical correlation analysis was applied to the linkage of multiple cognitive processes of mindfulness (Weick and Sutcliffe, 2001; 2007) and the governance dimensions of performance and conformance specified by the International Federation of Accountants (2009), underpinned by the moderating effects of five different components of MAS change, which yielded 13 significant relationships. The latter were subsequently analyzed for important gestalts (i.e., patterns) in the overall relationship, and assessed within the context of aligning professional accounting practices involving systems changes to the IFAC (2009) governance framework. These findings appear to have implications for improved governance structures in practice as well as offering a rich foundation for future research