Trapped electrons in Earth's outer Van Allen radiation belt are influenced profoundly by solar phenomena such as high-speed solar wind streams, coronal mass ejections (CME), and interplanetary (IP) ...shocks. In particular, strong IP shocks compress the magnetosphere suddenly and result in rapid energization of electrons within minutes. It is believed that the electric fields induced by the rapid change in the geomagnetic field are responsible for the energization. During the latter part of March 2015, a CME impact led to the most powerful geomagnetic storm (minimum Dst = −223 nT at 17 March, 23 UT) observed not only during the Van Allen Probe era but also the entire preceding decade. Magnetospheric response in the outer radiation belt eventually resulted in elevated levels of energized electrons. The CME itself was preceded by a strong IP shock whose immediate effects vis-a-vis electron energization were observed by sensors on board the Van Allen Probes. The comprehensive and high-quality data from the Van Allen Probes enable the determination of the location of the electron injection, timescales, and spectral aspects of the energized electrons. The observations clearly show that ultrarelativistic electrons with energies E greater than 6 MeV were injected deep into the magnetosphere at L approximately equals 3 within about 2 min of the shock impact. However, electrons in the energy range of approximately equals 250 keV to approximately equals 900 keV showed no immediate response to the IP shock. Electric and magnetic fields resulting from the shock-driven compression complete the comprehensive set of observations that provide a full description of the near-instantaneous electron energization.
Background
The first British Dietetic Association (BDA) guidelines for the dietary management of irritable bowel syndrome (IBS) in adults were published in 2012. Subsequently, there has been a wealth ...of new research. The aim of this work was to systematically review the evidence for the role of diet in the management of IBS and to update the guidelines.
Methods
Twelve questions relating to diet and IBS were defined based on review of the previous guideline questions, current evidence and clinical practice. Chosen topics were on healthy eating and lifestyle (alcohol, caffeine, spicy food, elimination diets, fat and fluid intakes and dietary habits), milk and dairy, dietary fibre, fermentable carbohydrates, gluten, probiotics and elimination diets/food hypersensitivity. Data sources were CINAHL, Cochrane Register of Controlled Trials, Embase, Medline, Scopus and Web of Science up to October 2015. Studies were assessed independently in duplicate using risk of bias tools specific to each included study based on inclusion and exclusion criteria for each question. National Health and Medical Research Council grading evidence levels were used to develop evidence statements and recommendations, in accordance with Practice‐based Evidence in Nutrition Global protocol used by the BDA.
Results
Eighty‐six studies were critically appraised to generate 46 evidence statements, 15 clinical recommendations and four research recommendations. The IBS dietary algorithm was simplified to first‐line (healthy eating, provided by any healthcare professional) and second‐line low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) to be provided by dietitian dietary advice.
Conclusions
These guidelines provide updated comprehensive evidence‐based details to achieve the successful dietary management of IBS in adults.
Abstract
Elemental composition in the solar wind reflects the fractionation processes at the Sun. In coronal mass ejections (CMEs) measured in the heliosphere, the elemental composition can vary ...between plasma of high and low ionization states as indicated by the average Fe charge state, 〈Q
Fe
〉. It is found that CMEs with higher ionized plasma, 〈Q
Fe
〉 greater than 12, are significantly more enriched in low first ionization potential (FIP) elements compared to their less ionized, 〈Q
Fe
〉 less than 12, counterparts. In addition, the CME elemental composition has been shown to vary along the solar cycle. However, the processes driving changes in elemental composition in the plasma are not well understood. To gain insight into this variation, this work investigates the effects of gravitational settling in the ejecta to examine how that process can modify signatures of the FIP effect found in CMEs. We examine the absolute abundances of C, N, O, Ne, Mg, Si, S, and Fe in CMEs between 1998 and 2011. Results show that the ejecta exhibits some gravitational settling effects in approximately 33% of all CME periods in plasma where the Fe abundance of the ejecta compared to the solar wind (Fe/H
CME
:Fe/H
SW
) is depleted compared to the C abundance (C/H
CME
:C/H
SW
). We also find gravitational settling is most prominent in CMEs during solar minimum; however, it occurs throughout the solar cycle. This study indicates that gravitational settling, along with the FIP effect, can become important in governing the compositional makeup of CME source regions.
We present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASAs Magnetospheric Multiscale mission with a focus on electron acceleration. From ...a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at approx. 7-9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. Electrons at energies higher than the threshold are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from approx. 130 keV to >500 keV, with each depolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that electron energization is dominated by betatron acceleration.
During the first months of observations, the Magnetospheric Multiscale Fly's Eye Energetic Particle Spectrometer instrument has observed several instances of electron acceleration up to greater than ...100 keV while in the vicinity of the dayside reconnection region. While particle acceleration associated with magnetic reconnection has been seen to occur up to these energies in the tail region, it had not yet been reported at the magnetopause. This study reports on observations of electron acceleration up to hundreds of keV that were recorded on 19 September 2015 around 1000 UT, in the midst of an X-line crossing. In the region surrounding the X-line, whistler-mode and broadband electrostatic waves were observed simultaneously with the appearance of highly energetic electrons which exhibited significant energization in the perpendicular direction. The mechanisms by which particles may be accelerated via reconnection-related processes are intrinsic to understanding particle dynamics among a wide range of spatial scales and plasma environments.
Energetic (greater than tens of keV) magnetospheric particle escape into the magnetosheath occurs commonly, irrespective of conditions that engender reconnection and boundary-normal magnetic fields. ...A signature observed by the Magnetospheric Multiscale (MMS) mission, simultaneous monohemispheric streaming of multiple species (electrons, H+, Hen+), is reported here as unexpectedly common in the dayside, dusk quadrant of the magnetosheath even though that region is thought to be drift-shadowed from energetic electrons. This signature is sometimes part of a pitch angle distribution evolving from symmetric in the magnetosphere, to asymmetric approaching the magnetopause, to monohemispheric streaming in the magnetosheath. While monohemispheric streaming in the magnetosheath may be possible without a boundary-normal magnetic field, the additional pitch angle depletion, particularly of electrons, on the magnetospheric side requires one. Observations of this signature in the dayside dusk sector imply that the static picture of magnetospheric drift-shadowing is inappropriate for energetic particle dynamics in the outer magnetosphere.
In this report, 528 cases of monkeypox across 16 countries are described. Rash, mucosal lesions, fever, lethargy, and lymphadenopathy were common clinical findings. Few patients were hospitalized.
How to cite this article: McKenzie Y.A., Alder A., Anderson W., Wills A., Goddard L., Gulia P., Jankovich E., Mutch P., Reeves L.B., Singer A. & Lomer M.C.E. on behalf of Gastroenterology Specialist ...Group of the British Dietetic Association. (2012) British Dietetic Association evidence‐based practice guidelines for the dietary management of irritable bowel syndrome in adults. J Hum Nutr Diet . 25, 260–274
Background: Irritable bowel syndrome (IBS) is a chronic debilitating functional gastrointestinal disorder. Diet and lifestyle changes are important management strategies. The aim of these guidelines is to systematically review key aspects of the dietary management of IBS, with the aim of providing evidence‐based guidelines for use by registered dietitians.
Methods: Questions relating to diet and IBS symptom management were developed by a guideline development group. These included the role of milk and lactose, nonstarch polysaccharides (NSP), fermentable carbohydrates in abdominal bloating, probiotics and empirical or elimination diets. A comprehensive literature search was conducted and relevant studies from January 1985 to November 2009 were identified using the electronic database search engines: Cinahl, Cochrane Library, Embase, Medline, Scopus and Web of Science. Evidence statements, recommendations, good practice points and research recommendations were developed.
Results: Thirty studies were critically appraised. A dietetic care pathway was produced following a logical sequence of treatment and formed the basis of these guidelines. Three lines of dietary management were identified. First line: Clinical and dietary assessment, healthy eating and lifestyle management with some general advice on lactose and NSP. Second line: Advanced dietary interventions to improve symptoms based on NSP, fermentable carbohydrates and probiotics. Third line: Elimination and empirical diets. Research recommendations were also identified relating to the need for adequately powered and well designed randomised controlled trials.
Conclusions: These guidelines provide evidence‐based details of how to achieve the successful dietary management of IBS.
Energetic electron injections are commonly observed in the premidnight to dawn regions in association with substorms. However, successive electron injections are generally separated in time by hours ...and are rarer in the dusk region of the inner magnetosphere. Early MMS energetic electron data taken in the dusk to premidnight regions above ~9 RE show many clusters of electron injections. These injections of 50–400 keV electrons have energy dispersion signatures indicating that they gradient and curvature drifted from earlier local times. We focus on burst rate data starting near 21:00 UT on 6 August 2015. A cluster of ~40 electron injections occurred in the following 4 h interval. The highest‐resolution data showed that the electrons in the injections were trapped and had bidirectional field‐aligned angular distributions. These injection clusters are a new phenomenon in this region of the magnetosphere.
Key Points
MMS FEEPS observes repetitive microinjections of 50‐400 keV electrons in the dusk to midnight region
The injected electrons have bidirectional field‐aligned angular distributions
The microinjections show clear energy‐time dispersions consistent with having gradient curvature drifted from the source region
We employ Magnetospheric Multiscale, Geostationary Operational Environmental and Los Alamos National Laboratory satellites, as well as the ground magnetometer networks over Greenland and North ...America to study a substorm on 9 August 2016 between 9 and 10 UT. We found that during the substorm two earthward flows, whose dipolarization‐injection fronts exceeded 6.5 and 4 Earth's radii (RE) in YGSM, impinged and rebounded from Earth's dipolar field lines at L=6–7 downtail, where L is the McIlwain number. The impingements and rebounds ended with a substorm current system of downward R1 and upward R2 currents which grew to azimuthally cover the whole North American continent. At the fronts, regions of enhanced negative j·E′ were formed and peaked toward the end of the impingements. These regions appeared to be conjugate with eastward moving aurora (along the growth phase arc and together with eastward drifting energetic electrons at geosynchronous equatorial orbit), which manifests ionospheric Ohmic losses.
Key Points
Two broad (6.5 and 4 RE in YGSM) dipolarization‐injection fronts impinged and rebounded from Earth's dipolar field lines near GEO during the same substorm
Downward R1 and upward R2 currents grew to azimuthally cover the whole North American continent in the course of the substorm
Regions of negative j·E′ (generator) peaked toward the end of the impingements and were conjugate to R2 auroral current (load)
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