234 research outputs found
Electron and proton heating by solar wind turbulence
Previous formulations of heating and transport associated with strong
magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate
internal energy equations for electrons and protons. Electron heat conduction
is included. Energy is supplied by turbulent heating that affects both
electrons and protons, and is exchanged between them via collisions. Comparison
to available Ulysses data shows that a reasonable accounting for the data is
provided when (i) the energy exchange timescale is very long and (ii) the
deposition of heat due to turbulence is divided, with 60% going to proton
heating and 40% into electron heating. Heat conduction, determined here by an
empirical fit, plays a major role in describing the electron data
Taxonomic clarification in W-Mediterranean Androcymbium (Colchicaceae): A. wyssianum sunk in the synonymy of A.gramineum and A.europaeum restored
Capsule dehiscence has been used as a diagnostic character for W Mediterranean species of Androcymbium. Depending on the state of capsule maturity, the character, however, can be ambiguous in herbarium material. Based on morphological, phenological and cpDNA characters it is shown that misinterpretation of the capsule as indehiscent in the type material of A. gramineum has led to serious taxonomic confusion. The combined analyses produced evidence that A. gramineum of the population from the type locality at Essaouira, Morocco, is conspecific with A. wyssianum. A. gramineum is therefore the correct name for the species with dehiscent capsules, whereas the populations with indehiscent capsules at the Atlantic coast north of Essaouira and in SE Spain represent a second species, which is correctly named A. europaeu
Solar Wind Turbulence and the Role of Ion Instabilities
International audienc
Aging of anisotropy of solar wind magnetic fluctuations in the inner heliosphere
We analyze the evolution of the interplanetary magnetic field spatial
structure by examining the inner heliospheric autocorrelation function, using
Helios 1 and Helios 2 "in situ" observations. We focus on the evolution of the
integral length scale (\lambda) anisotropy associated with the turbulent
magnetic fluctuations, with respect to the aging of fluid parcels traveling
away from the Sun, and according to whether the measured \lambda is principally
parallel (\lambda_parallel) or perpendicular (\lambda_perp) to the direction of
a suitably defined local ensemble average magnetic field B0. We analyze a set
of 1065 24-hour long intervals (covering full missions). For each interval, we
compute the magnetic autocorrelation function, using classical
single-spacecraft techniques, and estimate \lambda with help of two different
proxies for both Helios datasets. We find that close to the Sun,
\lambda_parallel < \lambda_perp. This supports a slab-like spectral model,
where the population of fluctuations having wavevector k parallel to B0 is much
larger than the one with k-vector perpendicular. A population favoring
perpendicular k-vectors would be considered quasi-two dimensional (2D). Moving
towards 1 AU, we find a progressive isotropization of \lambda and a trend to
reach an inverted abundance, consistent with the well-known result at 1 AU that
\lambda_parallel > \lambda_perp, usually interpreted as a dominant quasi-2D
picture over the slab picture. Thus, our results are consistent with driving
modes having wavevectors parallel to B0 near Sun, and a progressive dynamical
spectral transfer of energy to modes with perpendicular wavevectors as the
solar wind parcels age while moving from the Sun to 1 AU.Comment: Publishe
An evaluation of Canada's Compassionate Care Benefit from a family caregiver's perspective at end of life
<p>Abstract</p> <p>Background</p> <p>The goal of Canada's Compassionate Care Benefit (CCB) is to enable family members and other loved ones who are employed to take a temporary <it>secured </it>leave to care for a terminally ill individual at end of life. Successful applicants of the CCB can receive up to 55% of their average insured earnings, up to a maximum of CDN$435 per week, over a six week period to provide care for a gravely ill family member at risk of death within a six month period, as evidenced by a medical certificate. The goal of this study is to evaluate the CCB from the perspective of family caregivers providing care to individuals at end of life. There are three specific research objectives. Meeting these objectives will address our study purpose which is to make policy-relevant recommendations informed by the needs of Canadian family caregivers and input from other key stakeholders who shape program uptake. Being the first study that will capture family caregivers' experiences and perceptions of the CCB and gather contextual data with front-line palliative care practitioners, employers, and human resources personnel, we will be in a unique position to provide policy solutions/recommendations that will address concerns raised by numerous individuals and organizations.</p> <p>Methods</p> <p>We will achieve the research goal and objectives through employing utilization-focused evaluation as our methodology, in-depth interviews and focus groups as our techniques of data collection, and constant comparative as our technique of data analysis. Three respondent groups will participate: (1) family caregivers who are providing or who have provided end of life care via phone interview; (2) front-line palliative care practitioners via phone interview; and (3) human resources personnel and employers via focus group. Each of these three groups has a stake in the successful administration of the CCB. A watching brief of policy documents, grey literature, media reports, and other relevant items will also be managed throughout data collection.</p> <p>Discussion</p> <p>We propose to conduct this study over a three year period beginning in October, 2006 and ending in October, 2009.</p
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