365 research outputs found
Two-dimensional turbulence in magnetised plasmas
In an inhomogeneous magnetised plasma the transport of energy and particles
perpendicular to the magnetic field is in general mainly caused by quasi
two-dimensional turbulent fluid mixing. The physics of turbulence and structure
formation is of ubiquitous importance to every magnetically confined laboratory
plasma for experimental or industrial application. Specifically, high
temperature plasmas for fusion energy research are also dominated by the
properties of this turbulent transport. Self-organisation of turbulent vortices
to mesoscopic structures like zonal flows is related to the formation of
transport barriers that can significantly enhance the confinement of a fusion
plasma. This subject of great importance in research is rarely touched on in
introductory plasma physics or continuum dynamics courses. Here a brief
tutorial on 2D fluid and plasma turbulence is presented as an introduction to
the field, appropriate for inclusion in undergraduate and graduate courses.Comment: This is an author-created, un-copyedited version of an article
published in European Journal of Physics. IOP Publishing Ltd is not
responsible for any errors or omissions in this version of the manuscript or
any version derived from it. The definitive publisher authenticated version
is available online at doi: 10.1088/0143-0807/29/5/00
Adaptation of forest ecosystems to air pollution and climate change : a global assessment on research priorities.
Climate change and air pollution are two of the anthropogenic stressors that
require international collaboration. Influence mechanisms and combating
strategies towards them have similarities to some extent. Impacts of air pollution
and climate change have long been studied under IUFRO Research Group
7.01 and state of the art findings are presented at biannual meetings. Monitoring,
modelling, assessment of multiple stressors, ecophysiology, and nutrient
cycles have been thoroughly studied aspects of climate change and air pollution
research for a long time under the umbrella of IUFRO RG 7.01. Recently,
social and economic issues together with water relations are gaining more attention
in parallel with science requirements on adaptation. In this paper, we
summarise the main research needs emphasized at the recent 24th IUFRO RG
7.01 Conference titled ?Adaptation of Forest Ecosystems to Air Pollution and
Climate Change?. One important conclusion of the conference was the need
for information on nutritional status of forest stands for sustainable forest
management. It has been suggested to maintain long-term monitoring programs
and to account for the effects of extreme years, and past and present management
practices. Long-term monitoring can also help to understand the effects
of forestry treatments on the nutrient and water budgets of the ecosystems
which may enable to improve management practices like water saving silviculture
A Shot in the Dark: Failing to Recognize the Link Between Physical and Mental Illness
A 74-year-old widowed white man with chronic rheumatoid arthritis presented with nausea and weight loss. He was diagnosed with failure to thrive and admitted for hydration. Misoprostol was determined to be the etiology of his symptoms and he was discharged home. Three days later, he killed himself with a gunshot to the head. Clinicians often fail to recognize those at high risk for suicide. Suicidal risk is increased in both psychiatric and physical illness, and particularly when both are present. Psychiatric illness, particularly depression, often underlies chronic medical illness. The purpose of this case report is to remind health care providers of the strong association between depression and chronic medical illness, and to consider this in all patients, including those who present solely with physical symptoms. Recognizing this association and screening for it, as recommended by the U.S. Preventive Services Task Force, may prevent the unnecessary tragedy of suicide
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