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Accurate modelling of electron transport in plasmas, plasma-liquid and plasma-tissue interactions requires (i) the existence of accurate and complete sets of cross-sections, and (ii) an accurate treatment of electron transport in these gaseous and soft-condensed phases. In this study we present progress towards the provision of self-consistent electron-biomolecule cross-section sets representative of tissue, including water and THF, by comparison of calculated transport coefficients with those measured using a pulsed-Townsend swarm experiment. Water-argon mixtures are used to assess the self-consistency of the electron-water vapour cross-section set proposed in de Urquijo et al (2014 J. Chem. Phys. 141 014308). Modelling of electron transport in liquids and soft-condensed matter is considered through appropriate generalisations of Boltzmann's equation to account for spatial-temporal correlations and screening of the electron potential. The ab initio formalism is applied to electron transport in atomic liquids and compared with available experimental swarm data for these noble liquids. Issues on the applicability of the ab initio formalism for krypton are discussed and addressed through consideration of the background energy of the electron in liquid krypton. The presence of self-trapping (into bubble/cluster states/solvation) in some liquids requires a reformulation of the governing Boltzmann equation to account for the combined localised-delocalised nature of the resulting electron transport. A generalised Boltzmann equation is presented which is highlighted to produce dispersive transport observed in some liquid systems.

AIM: To examine the relationship between unsettled infant behaviour and fathers' depressive symptoms, cognitions surrounding infant sleep (anger, doubt), and personal sleep, in a community cohort. METHODS: Data were collected from 102 fathers of healthy infants at 4 weeks, 4 months and 6 months of age. Measures included father report of infant sleep and crying problems, depressive symptoms, cognitions about infant sleep and own sleep quality and quantity. Data were analysed using adjusted regression models. RESULTS: Sleep problems at 4 months of age were associated with increased depressive symptoms (adjusted mean difference 2.64 (1.27-4.00)), doubt (adjusted mean difference 1.82 (0.40-3.25)), anger (adjusted mean difference 1.86 (0.51-3.20)), poor personal sleep quantity (adjusted odds ratio (OR) 0.21; 95% confidence interval (CI) 0.09-0.51) and quality (adjusted OR 0.20; 95% CI 0.08-0.51); and at 6 months of age, with increased depressive symptoms (adjusted mean difference 2.56 (1.28-3.84)), anger (adjusted mean difference 1.63 (0.40-2.87)), poor personal sleep quantity (adjusted OR 0.14; 95% CI 0.05-0.38) and quality (adjusted OR 0.28; 95% CI 0.11-0.72). Infant cry problems at 4 months were associated with increased anger (adjusted mean difference 1.98 (0.60-3.36)) and doubt (adjusted mean difference 1.55 (0.05-3.05)); and at 6 months, with increased depressive symptoms (adjusted mean difference 3.04 (1.59-4.69)), anger (adjusted mean difference 2.73 (1.29-4.17)) and less personal sleep (adjusted OR 0.22; 95% CI 0.07-0.71). CONCLUSION: Fathers of unsettled infants reported greater anger towards their infant and increased depressive symptoms by 4 months infant age, with these symptoms persisting 2 months later. Evidence-based interventions are needed for these fathers.

I Adamovich et al 2017 J. Phys. D: Appl. Phys. 50 323001, Journal of Physics D: Applied Physics published the first Plasma Roadmap in 2012 consisting of the individual perspectives of 16 leading experts in the various sub-fields of low temperature plasma science and technology. The 2017 Plasma Roadmap is the first update of a planned series of periodic updates of the Plasma Roadmap. The continuously growing interdisciplinary nature of the low temperature plasma field and its equally broad range of applications are making it increasingly difficult to identify major challenges that encompass all of the many sub-fields and applications. This intellectual diversity is ultimately a strength of the field. The current state of the art for the 19 sub-fields addressed in this roadmap demonstrates the enviable track record of the low temperature plasma field in the development of plasmas as an enabling technology for a vast range of technologies that underpin our modern society. At the same time, the many important scientific and technological challenges shared in this roadmap show that the path forward is not only scientifically rich but has the potential to make wide and far reaching contributions to many societal challenges.

The topical issue on Advances in Positron and Electron Scattering” combines contributionsfrom POSMOL 2015 together with others devoted to celebrate the unprecedented scientificcareers of our loyal colleagues and trusted friends Steve Buckman (Australian NationalUniversity, Australia) and Michael Allan (University of Fribourg, Switzerland) on theoccasion of their retirements. POSMOL 2015, the XVIII International Workshop on Low-EnergyPositron and Positronium Physics and the XIX International Symposium on Electron-MoleculeCollisions and Swarms, was held at Universidade NOVA de Lisboa, Lisboa, Portugal, from17–20 July 2015. The international workshop and symposium allowed to achieve a veryprivileged forum of sharing and developing our scientific expertise on current aspects ofpositron, positronium and antiproton interactions with electrons, atoms, molecules andsolid surfaces, and related topics, as well as electron interactions with molecules inboth gaseous and condensed phases. Particular topics include studies of electroninteractions with biomolecules, electron induced surface chemistry and the study of plasmaprocesses. Recent developments in the study of swarms are also fully addressed. EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2016

The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range-a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the â gas-phaseâ (tm) assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations.

The accuracy and completeness of electron impact cross-sections in water and tetrahydrofuran are assessed through comparison with experimental electron transport coefficients using the pulsed Townsend experiment.

We present a study of electron and positron transport in water in both the gaseous and liquid states using a Boltzmann equation analysis and a Monte-Carlo simulation technique. We assess the importance of coherent scattering processes when considering tra

In this paper we make a parallel between the swarm method in physics of ionized gases and modeling of positrons in radiation therapy and diagnostics. The basic idea is to take advantage of the experience gained in the past with electron swarms and to use

Collisions of electrons, atoms, molecules, photons and ions are the basic processes in plasmas and ionized gases in general. This is especially valid for low temperature collisional plasmas. Kinetic phenomena in transport are very sensitivitive to the shape of the cross sections and may at the same time affect the macroscopic applications. We will show how transport theory or simulation codes, phenomenology, kinetic phenomena and transport data may be used to improve our knowledge of the cross sections, our understanding of the plasma models, application of the swarm physics in ionized gases and similar applications to model and improve gas filled traps of positrons. Swarm techniques could also be a starting point in applying atomic and molecular data in models of electron or positron therapy/diagnostics in radiation related medicine.

BACKGROUND: Management of Type 1 diabetes comes with substantial personal and psychological demands particularly during adolescence, placing young people at significant risk for mental health problems. Supportive parenting can mitigate these risks, however the challenges associated with parenting a child with a chronic illness can interfere with a parent's capacity to parent effectively. Interventions that provide support for both the adolescent and their parents are needed to prevent mental health problems in adolescents; to support positive parent-adolescent relationships; and to empower young people to better self-manage their illness. This paper presents the research protocol for a study evaluating the efficacy of the Nothing Ventured Nothing Gained online adolescent and parenting intervention which aims to improve the mental health outcomes of adolescents with Type 1 diabetes. METHOD/DESIGN: A randomized controlled trial using repeated measures with two arms (intervention and wait-list control) will be used to evaluate the efficacy and acceptability of the online intervention. Approximately 120 adolescents with Type 1 diabetes, aged 13-18 years and one of their parents/guardians will be recruited from pediatric diabetes clinics across Victoria, Australia. Participants will be randomized to receive the intervention immediately or to wait 6 months before accessing the intervention. Adolescent, parent and family outcomes will be assessed via self-report questionnaires at three time points (baseline, 6 weeks and 6 months). The primary outcome is improved adolescent mental health (depression and anxiety). Secondary outcomes include adolescent behavioral (diabetes self-management and risk taking behavior), psychosocial (diabetes relevant quality of life, parent reported child well-being, self-efficacy, resilience, and perceived illness benefits and burdens); metabolic (HbA1c) outcomes; parent psychosocial outcomes (negative affect and fatigue, self-efficacy, and pare

We review the current status of positron cross sections for collisions with atoms and molecules from the viewpoint of their use in studies of positron transport processes in gases, liquids and human tissue. The data include cross sections for positron sca

In this study, we present a complete set of positron interaction cross sections for scattering from Ar, for incident energies ranging from 0 to 10 keV. Experimental data have been critically reviewed from previous experiments performed at the Australian National University and University College London. Differential and integral cross sections, including the effect of positronium formation, have been calculated by using two different optical potential methods. The results of these calculations, in combination with experimental cross sections and experimental energy-loss spectra, have been established as input parameters for an event-by-event Monte Carlo simulation procedure to generate single positron tracks in argon. The reliability of this method to obtain energy deposition models at the nano-scale is also discussed.

This work reports on a new series of calculations of positron transport properties in molecular hydrogen under the influence of spatially homogeneous electric field. Calculations are performed using a Monte Carlo simulation technique and multi term theory for solving the Boltzmann equation. Values and general trends of the mean energy, drift velocity and diffusion coefficients as a function of the reduced electric field E/n0 are reported here. Emphasis is placed on the explicit and implicit effects of positronium (Ps) formation on the drift velocity and diffusion coefficients. Two important phenomena arise; first, for certain regions of E/n0 the bulk and flux components of the drift velocity and longitudinal diffusion coefficient are markedly different, both qualitatively and quantitatively. Second, and contrary to previous experience in electron swarm physics, there is negative differential conductivity (NDC) effect in the bulk drift velocity component with no indication of any NDC for the flux component. In order to understand this atypical manifestation of the drift and diffusion of positrons in H2 under the influence of electric field, the spatially dependent positron transport properties such as number of positrons, average energy and velocity and spatially resolved rate for Ps formation are calculated using a Monte Carlo simulation technique. The spatial variation of the positron average energy and extreme skewing of the spatial profile of positron swarm are shown to play a central role in understanding the phenomena.