High‐resolution in situ measurements from the three Swarm spacecraft, in a string‐of‐pearls configuration, provide new insights about the combined role of flow channel events and particle impact ...ionization in creating F region electron density structures in the northern Scandinavian dayside cusp. We present a case of polar cap patch formation where a reconnection‐driven low‐density relative westward flow channel is eroding the dayside solar‐ionized plasma but where particle impact ionization in the cusp dominates the initial plasma structuring. In the cusp, density features are observed which are twice as dense as the solar‐ionized background. These features then follow the polar cap convection and become less structured and lower in amplitude. These are the first in situ observations tracking polar cap patch evolution from creation by plasma transport and enhancement by cusp precipitation, through entrainment in the polar cap flow and relaxation into smooth patches as they approach the nightside auroral oval.
Key Points
Novel technique using string‐of‐pearls spacecraft to resolve plasma dynamics
In situ Swarm observations of the creation and evolution of polar cap patches
Cusp ionization can dominate the creation and initial structuring of patches
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To provide new insights into the relationship between geomagnetic conditions and plasma irregularity scale‐sizes, high‐latitude irregularity spectra are computed using a novel Incoherent Scatter ...Radar (ISR) technique. This new technique leverages: (a) the ability of phased array Advanced Modular ISR (AMISR) technology to collect volumetric measurements of plasma density, (b) the slow F‐region cross‐field plasma diffusion at scales greater than 10 km, and (c) the high dip angle of geomagnetic field lines at high‐latitudes. The resulting irregularity spectra are of a higher spatiotemporal resolution than what has been previously possible with ISRs. Spatial structures as small as 20 km are resolved in less than 2 minutes (depending on the radar mode). In this work, we focus on Resolute Bay ISR‐North (RISR‐N) observations operating in the “imaginglptight” mode. In addition to having an unprecedented view of the size and occurrence of irregularities as they traverse the polar cap, we find that as the F‐region plasma density decreases below approximately 2.5 × 1010 m−3 at 350 km altitude the spectral power shifts to scale‐sizes lower than 50 km. Additionally, near magnetic local noon, the spectral power shifts to scales greater than 50 km, and from 15 to 6 magnetic local time, the spectral power shifts to scales lower than 50 km. This reflects the role of photoionization dominating high‐latitude ionospheric structuring in the polar cap.
Key Points
A novel mapping technique is developed to compute high latitude ionospheric irregularity spectra at a high spatiotemporal resolution
The spectral power shifts to structures smaller than 50 km at low plasma densities and from dusk to dawn
Photoionization dominates structuring in the polar cap and creates structures 100 km and larger
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Results from the NASA Van Allen Probes mission indicate extensive observations of mirror/drift‐mirror (M/D‐M hereafter) unstable plasma regions in the night‐side inner magnetosphere. Said plasmas lie ...on the threshold between the kinetic and frozen‐in plasma regimes and have favorable conditions for the formation of M/D‐M modes and subsequent ultralow frequency (ULF) wave signatures in the surrounding plasma. We present the results of a climatological analysis of plasma‐γ (anisotropy measure) and total plasma‐β (ratio of particle to magnetic field pressure) in regard to the satisfaction of instability conditions on said M/D‐M modes under bi‐Maxwellian distribution assumption, and ascertain the most likely region for such plasmas to occur. Our results indicate a strong preference for the premidnight sector of the night‐side magnetosphere, with events ranging in time scales from half a minute (roughly 200 km in scale size) to several hours (multiple Earth radii). The statistical distribution of these plasma regions explicitly identifies the source region of “storm time Pc5 ULF waves” and suggests an alternative mechanism for their generation in the night‐side inner magnetosphere.
Plain Language Summary
We study the plasma characteristics of the near Earth magnetosphere and determine whether or not the conditions are met for a certain type of plasma instability called the mirror/drift‐mirror mode instability, which can transfer energy between plasma particles and electromagnetic fields. This instability is similar to a bubble, and drifts through the near Earth plasma environment. While it drifts, it can create large waves in the plasma, known as ultralow frequency (ULF) waves. ULF waves can then interact with other particles in the magnetosphere, or be detected by instruments on the Earth's surface. We investigated data measured by instrumentation on the NASA Van Allen Probes spacecraft to make this determination. We found that the conditions in a certain region of the magnetosphere are favorable for this specific instability, which is important in understanding ULF waves observed from this region.
Key Points
Mirror mode unstable plasmas occur in the dusk‐to‐midnight inner magnetosphere
Mirror‐unstable plasmas are likely due to magnetotail injections
Mirror mode propagation can lead to ultra‐low frequency (ULF) mode generation
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background: Dogs with protein-losing enteropathy (PLE) have previously been reported to present with thromboembolism; however, the prevalence and pathogenesis of hypercoagulability in dogs with PLE ...have not been investigated so far. Hypothesis: Dogs with PLE are hypercoagulable compared with healthy control dogs. Animals: Fifteen dogs with PLE. Thirty healthy dogs served as controls (HC). Methods: A prospective study was performed including 15 dogs with PLE. All dogs were scored using the canine chronic enteropathy activity index (CCECAI). Thromboelastography (TEG) and other measures of coagulation were evaluated. Recalcified, unactivated TEG was performed and reaction time (R), kinetic time (K), alpha angle (α), and maximum amplitude (MA) values were recorded. Nine dogs were reassessed after initiation of immunosuppressive treatment. Results: All dogs with PLE in the study were hypercoagulable with decreased R (PLE: median 7.8, range 2.4–11.2; HC: 14.1 9.1–20.3), decreased K (PLE: 2.5 0.8–5.2; HC: 8.25 4.3–13.1), increased α (PLE: 56.7 38.5–78.3; HC: 25.6 17–42.4), and increased MA (PLE: 68.2 54.1–76.7; HC: 44.1, 33.5–49) (all P < .001). Median antithrombin (AT) concentration was borderline low in PLE dogs; however, mean serum albumin concentration was severely decreased (mean 1.67 g/dL ± 5.1, reference range 2.8–3.5 g/dL). Despite a significant improvement in serum albumin and CCECAI, all 9 dogs with PLE were hypercoagulable at re-examination. Conclusions and Clinical Importance: The hypercoagulable state in dogs with PLE cannot be solely attributed to loss of AT. Despite good clinical response to treatment, dogs remained hypercoagulable and could therefore be predisposed to thromboembolic complications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Polar cap ionospheric plasma flow studies often focus on large‐scale averaged properties and neglect the mesoscale component. However, recent studies have shown that mesoscale flows are often found ...to be collocated with airglow patches. These mesoscale flows are typically a few hundred meters per second faster than the large‐scale background and are associated with major auroral intensifications when they reach the poleward boundary of the nightside auroral oval. Patches often also contain ionospheric signatures of enhanced field‐aligned currents and localized electron flux enhancements, indicating that patches are associated with magnetosphere‐ionosphere coupling on open field lines. However, magnetospheric measurements of this coupling are lacking, and it has not been understood what the magnetospheric signatures of patches on open field lines are. The work presented here explores the magnetospheric counterpart of patches and the role these structures have in plasma transport across the open field‐line region in the magnetosphere. Using red‐line emission measurements from the Resolute Bay Optical Mesosphere Thermosphere Imager, and magnetospheric measurements made by the Cluster spacecraft, conjugate events from 2005 to 2009 show that lobe measurements on field lines connected to patches display (1) electric field enhancements, (2) Region 1 sense field‐aligned currents, (3) field‐aligned enhancements in soft electron flux, (4) downward Poynting fluxes, and (5) in some cases enhancements in ion flux, including ion outflows. These observations indicate that patches highlight a localized fast flow channel system that is driven by the magnetosphere and propagates from the dayside to the nightside, most likely being initiated by enhanced localized dayside reconnection.
Key Points
Airglow patches detected using the Resolute Bay imager correspond to lobe structures discovered in Cluster spacecraft observations
Lobe structures over patches contain locally enhanced flows, R‐1 sense field‐aligned currents, and field‐aligned soft electron flux enhancements
The lobe structures are driven by the magnetosphere, likely due to enhanced localized dayside reconnection and subsequent poleward propagation
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The formation of polar cap density enhancements, such as tongues‐of‐ionization (TOIs), are often attributed to enhanced dayside reconnection and convection due to solar wind changes. However, ...ionospheric poleward moving density enhancements can also form in the absence of changes in the solar wind. This study examines how TOI and patch events that are not triggered by solar wind changes relate to magnetospheric processes, specifically substorms. Based on total electron content and Super Dual Auroral Radar Network (SuperDARN) observations, we find substorms that occur at the same time as TOIs are associated with sudden enhancements in dayside poleward flows during the substorm expansion phase. Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) observations also show enhanced field‐aligned currents (FACs) that extend into the dayside ionosphere during this period. We suggest that the global enhancement of FACs and convection during these substorms are the drivers of these TOIs by enhancing dayside convection and transporting high‐density lower‐latitude plasma into the polar cap. However, we also find that not all substorms are coincident with polar cap density enhancements. A superposed epoch study showed that the AL index for TOIs during substorms is not particularly stronger than substorms without TOIs, but epoch studies of AMPERE observations do show events with TOIs to have a higher total FAC on both the dayside and nightside. Our results show the importance of TOI formation during substorms when solar wind drivers are absent, and the importance of considering substorms in the global current system. This work also shows the need to incorporate substorms into models of high‐latitude global convection and currents.
Key Points
Enhanced dayside flows without interplanetary magnetic field changes can occur during substorms
Dayside plasma flows during substorms can transport photoionized plasma into the polar cap
Substorms impact dayside currents and patches despite being typically associated with the nightside
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Extremely elevated ion temperatures observed with the Poker Flat and Resolute Bay incoherent scatter radars in the E and F regions of the polar ionosphere are discussed. Our observations include ...one‐dimensional, line‐of‐sight ion temperatures (Ti,1d) that at times can rise to up to ∼8000°K. While examining the accuracy of the derived temperatures is difficult due to the several potential sources of error and uncertainty, we find that at altitudes of ∼130–250 km the line‐of‐sight ion temperatures obtained at relatively small aspect angles (for instance, at 22.5° away from the magnetic field direction) are below the expected values for the average or three‐dimensional ion temperatures (Ti). We find that this difference matches well with the theoretical expectation from anisotropic ion velocity distributions that emerge from polarization elastic scattering collisions between NO+ and N2. These results are therefore the clearest detection of anisotropic ion velocity distributions with the Poker Flat Incoherent Scatter Radar and Resolute Bay Incoherent Scatter Radar facilities. Moreover, at higher altitudes (>∼300 km), where the resonant charge exchange collisions prevail, and for a very high ion temperature event (Ti∼8000°K), we observe that the incoherent scatter radar (ISR) spectra obtained at large aspect angles (e.g., 55°) look like those expected from non‐Maxwellian plasma. At similar altitudes, the measured one‐dimensional temperatures at an aspect angle of 22.5° are found to exceed the expected values from the frictional heating and resonant charge exchange collisions by about 1000°K. A portion of this offset is thought to reflect the role of Coulomb collisions.
Key Points
Ion frictional heating in the high‐latitude ionosphere is studied by using incoherent scatter radars
Anisotropic and non‐Maxwellian ion velocity distributions are inferred from PFISR/RISR measurements
Effect of Coulomb collisions on the ion distribution function is inferred from the derived ion temperatures
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
ABSTRACT Most of the 3,000 named species in the genus Cercospora have no known sexual stage, although a Mycosphaerella teleomorph has been identified for a few. Mycosphaerella is an extremely large ...and important genus of plant pathogens, with more than 1,800 named species and at least 43 associated anamorph genera. The goal of this research was to perform a large-scale phylogenetic analysis to test hypotheses about the past evolutionary history of Cercospora and Mycosphaerella. Based on the phylogenetic analysis of internal transcribed spacer (ITS) sequence data (ITS1, 5.8S rRNA gene, ITS2), the genus Mycosphaerella is monophyletic. In contrast, many anamorph genera within Mycosphaerella were polyphyletic and were not useful for grouping species. One exception was Cercospora, which formed a highly supported monophyletic group. Most Cercospora species from cereal crops formed a subgroup within the main Cercospora cluster. Only species within the Cercospora cluster produced the toxin cercosporin, suggesting that the ability to produce this compound had a single evolutionary origin. Intraspecific variation for 25 taxa in the Mycosphaerella clade averaged 1.7 nucleotides (nts) in the ITS region. Thus, isolates with ITS sequences that differ by two or more nucleotides may be distinct species. ITS sequences of groups I and II of the gray leaf spot pathogen Cercospora zeae-maydis differed by 7 nts and clearly represent different species. There were 6.5 nt differences on average between the ITS sequences of the sorghum pathogen Cercospora sorghi and the maize pathogen Cercospora sorghi var. maydis, indicating that the latter is a separate species and not simply a variety of Cercospora sorghi. The large monophyletic Mycosphaerella cluster contained a number of anamorph genera with no known teleomorph associations. Therefore, the number of anamorph genera related to Mycosphaerella may be much larger than suspected previously.
•Care for people with epilepsy and intellectual disability (ID) is ‘fragmented’.•People with epilepsy and ID often have complex needs and multiple co-morbidities.•People with epilepsy and ID wait ...longer for routine investigations.•A minority of clinicians do not consider some non-pharmacological interventions.•Recommendations are made to improve care provision for people with epilepsy and ID.
This article reflects the report by the British Branch of the International League Against Epilepsy (ILAE) Working Group on services for adults with epilepsy and intellectual disability (ID). Its terms of reference was to explore the current status of aspects of the care of people with an ID and epilepsy.
Survey content was developed from key themes identified by consensus of the working group. An electronic survey was distributed via email. The sample population was the membership of the ILAE UK, Royal College of Psychiatrists (RCPsych) Faculty of ID, Epilepsy Nurses Association (ESNA), and the Association of British Neurologists (ABN). Following a six week response period the data was then collated, anonymised and distributed to the working group in order that opinion statements could be gathered.
The time taken for individuals with both new-onset and established epilepsy to undergo routine investigation was commonly at least 1–3 months, far beyond recommendations made by NICE (CG20). A small minority of clinicians would not consider non-pharmacological interventions including epilepsy surgery, vagus nerve stimulation, and ketogenic diet for this population. Almost universally responders are actively involved in the assessment and management of key risk areas including risk of drowning, hospitalization, medication side effects, and sudden unexpected death in epilepsy (SUDEP).
This investigation identifies key themes and recommendations relating to care delivery and meeting the complex needs of people with ID and epilepsy. Adults with ID and epilepsy appear to exist in a unique, but inadequate, segment of epilepsy care delivery.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Under strong electric field conditions often found at high latitudes, the ion velocity distribution of the weakly ionized F region plasma can differ enough from a Maxwellian shape to substantially ...change incoherent scatter (IS) spectra and thus the analysis of those spectra. With the goal to provide a quantitative and reliable description of the IS spectra, this study directly uses for the first time an advanced Monte Carlo calculation of the ion velocity distribution to derive IS spectra for a range of electric fields and aspect angles. For most cases the spectra associated with NO+ maintains a shape that closely resembles that of a spectrum derived from a Maxwellian distribution with the same line‐of‐sight ion temperature as the equivalent Monte Carlo simulated distribution. This study also fully characterizes the spectral shape as well as the ion temperature and its anisotropy for two different models of the resonant charge exchange between O+ and O. It confirms that the distortions from the Maxwellian shape can be substantial for this particular interaction. The distortions are also such that along the magnetic field direction, the extracted apparent electron temperature is always greater than the real temperature. This work also includes a determination of the stability of the plasma against magnetic field‐aligned electrostatic instabilities. It is found that the NO+ distribution is always stable, whereas the O+ distribution may or may not be stable, depending on the model chosen for the resonant charge exchange cross section in collisions with the background atomic oxygen gas.
Key Points
Accurate computation of incoherent scatter spectra under strong ion frictional heating
Along the magnetic field, Te/Ti can be seriously overestimated if non‐Maxwellian effects are ignored
Simulations show that the plasma is more stable against electrostatic waves than previously thought
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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