The effect of variations in the magnetic field direction from turbulence on kinetic-scale instabilities

At kinetic scales in the solar wind, instabilities transfer energy from particles to fluctuations in the electromagnetic fields while restoring plasma conditions towards thermodynamic equilibrium. We investigate the interplay between background turbulent fluctuations at the small-scale end of the inertial range and kinetic instabilities acting to reduce proton temperature anisotropy. We analyse in situ solar wind observations from the Solar Orbiter mission to develop a measure for variability in the magnetic field direction. We find that non-equilibrium conditions sufficient to cause micro-instabilities in the plasma coincide with elevated levels of variability. We show that our measure for the fluctuations in the magnetic field is non-ergodic in regions unstable to the growth of temperature anisotropy-driven instabilities. We conclude that the competition between the action of the turbulence and the instabilities plays a significant role in the regulation of the proton-scale energetics of the solar wind. This competition depends not only on the variability of the magnetic field but also on the spatial persistence of the plasma in non-equilibrium conditions

Climate–groundwater dynamics inferred from GRACE and the role of hydraulic memory

Groundwater is the largest store of freshwater on Earth after the cryosphere and provides a substantial proportion of the water used for domestic, irrigation and industrial purposes. Knowledge of this essential resource remains incomplete, in part, because of observational challenges of scale and accessibility. Here we examine a 14-year period (2002–2016) of Gravity Recovery and Climate Experiment (GRACE) observations to investigate climate–groundwater dynamics of 14 tropical and sub-tropical aquifers selected from WHYMAP's (Worldwide Hydrogeological Mapping and Assessment Programme) 37 large aquifer systems of the world. GRACE-derived changes in groundwater storage resolved using GRACE Jet Propulsion Laboratory (JPL) mascons and the Community Land Model's land surface model are related to precipitation time series and regional-scale hydrogeology. We show that aquifers in dryland environments exhibit long-term hydraulic memory through a strong correlation between groundwater storage changes and annual precipitation anomalies integrated over the time series; aquifers in humid environments show short-term memory through strong correlation with monthly precipitation. This classification is consistent with estimates of groundwater response times calculated from the hydrogeological properties of each system, with long (short) hydraulic memory associated with slow (rapid) response times. The results suggest that groundwater systems in dryland environments may be less sensitive to seasonal climate variability but vulnerable to long-term trends from which they will be slow to recover. In contrast, aquifers in humid regions may be more sensitive to climate disturbances such as drought related to the El Niño–Southern Oscillation but may also be relatively quick to recover. Exceptions to this general pattern are traced to human interventions through groundwater abstraction. Hydraulic memory is an important factor in the management of groundwater resources, particularly under climate change

Books

Valuable distillations of other people's experiencesHow To Do It. Vol. 3. Pp. x + 203. Illustrated. £9 (including postage by air). London: BMJ. 1990. (Also available from Libriger Book Distributors, Bloemfontein.)Medical dictionaryConcise Medical Dictionary. 3rd ed. Ed. By Elizabeth A. Martin. Pp. 1-759. Oxford: Oxford University Press. 1990.Paediatric cardiologyPrevention in Childhood and Youth of Adult Cardiovascular Diseases: Time for Action. Ed. by WHO Expert Committee. Pp. 1 - 105. Illustrated. Sw. Fr. 12. Geneva: WHO.1990.Contraceptive safety Safety Requirements for Contraceptive Steroids. Ed. by F. Michal. pp. xv - 467. Illustrated. £65,00. Cambridge: Cambridge University Press. 1989.Psychiatry Textbook of Psychiatry. Ed. by P. J. V. Beumont and R. B. Hampshire. Pp. x + 520. Illustrated. PriCe £29,50. Oxford: Blackwell Scientific Publications. 1989

Speech rhythm and language acquisition: an amplitude modulation phase hierarchy perspective.

Language lies at the heart of our experience as humans and disorders of language acquisition carry severe developmental costs. Rhythmic processing lies at the heart of language acquisition. Here, I review our understanding of the perceptual and neural mechanisms that support language acquisition, from a novel amplitude modulation perspective. Amplitude modulation patterns in infant- and child-directed speech support the perceptual experience of rhythm, and the brain encodes these rhythm patterns in part via neuroelectric oscillations. When brain rhythms align themselves with (entrain to) acoustic rhythms, speech intelligibility improves. Recent advances in the auditory neuroscience of speech processing enable studies of neuronal oscillatory entrainment in children and infants. The "amplitude modulation phase hierarchy" theoretical perspective on language acquisition is applicable across languages, and cross-language investigations adopting this novel perspective would be valuable for the field

A nutrition strategy to reduce the burden of diet related disease: access to dietician services must complement population health approaches

Poor diet quality is implicated in almost every disease and health issue. And yet, in most advanced market economies diet quality is poor, with a minority meeting guidelines for healthy eating. Poor diet is thus responsible for substantial disease burden. Societies have at their disposal a range of strategies to influence diet behaviors. These can be classified into: (i) population level socio-educational approaches to enhance diet knowledge; (ii) pricing incentives (subsidies on healthy foods, punitive taxes on unhealthy foods); (iii) regulations to modify the food environment, and (iv) the provision of clinical dietetic services. There is little evidence that societies are active in implementing the available strategies. Advertising of “junk foods” is largely unchecked, contrasting with strict controls on advertising tobacco products, which also attract punitive taxes. Access to dieticians is restricted in most countries, even in the context of universal health care. In Australia in 2011 there were just 2,969 practicing dieticians/nutritionists or 1.3 clinicians per 10,000 persons, compared with 5.8 physiotherapists per 10,000 persons, 14.8 general practitioners (family physicians) per 10,000 persons or 75 nurses per 10,000 persons. It is time to implement comprehensive national nutrition strategies capable of effecting change. Such strategies need to be multi-component, incorporating both public health approaches and expanded publicly funded dietetic services. Access to individualized dietetic services is needed by those at risk, or with current chronic conditions, given the complexity of the diet message, the need for professional support for behavior change and to reflect individual circumstances. The adoption of a comprehensive nutrition strategy offers the promise of substantial improvement in diet quality, better health and wellbeing and lower health care costs

Preventing mental health problems in offspring by targeting dietary intake of pregnant women

The concept of \u27early life programming\u27 considers the importance of very early environmental exposures throughout the gestational period on the subsequent health outcomes of offspring. The role of maternal dietary intake, specifically, has been highlighted after recent studies have shown maternal diet quality to predict mental health problems in offspring. Even in the pre-conception period, maternal nutrition can have permanent and sustained phenotypic consequences for offspring