A5063426834- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Protist diversity and phylogeny
- Marine Invertebrate Physiology and Ecology
- Oceanographic and Atmospheric Processes
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Atomic and Subatomic Physics Research
- GNSS positioning and interference
- Biocrusts and Microbial Ecology
- Microbial Community Ecology and Physiology
- Botanical Research and Chemistry
- Particle Accelerators and Free-Electron Lasers
- Plant and Fungal Species Descriptions
- Geophysical and Geoelectrical Methods
- Marine Ecology and Invasive Species
- Diatoms and Algae Research
- Inertial Sensor and Navigation
- Botany, Ecology, and Taxonomy Studies
- Bryophyte Studies and Records
- Cerebrovascular and Carotid Artery Diseases
- Mediterranean and Iberian flora and fauna
- Cellular Mechanics and Interactions
Canadian Space Agency
2022-2024
University of Calgary
2014-2021
University of Saskatchewan
2018-2021
John Wiley & Sons (United States)
2019
Charles River Laboratories (Netherlands)
2019
University of Notre Dame
1986-2010
University of Tasmania
1870
A glowing ribbon of purple light running east-west in the night sky has recently been observed by citizen scientists. This narrow, subauroral, visible structure, distinct from traditional auroral oval, was largely undocumented scientific literature and little known about its formation. Amateur photo sequences showed colors distinctly different common types aurora occasionally indicated magnetic field-aligned substructures. Observations Swarm satellite as it crossed arc have revealed an...
Embryogenesis in hydra includes a variable period of dormancy; and this period, as well subsequent stages through hatching, takes place within thick cuticle that hinders observation. Thus, although the early development have been well-characterized qualitatively, middle later are only poorly understood. Here, we provide detailed description embryogenesis, including time required to traverse each stages, changes occur type number cells throughout stages. The events cleavage gastrulation first...
Abstract Little is currently known about the optical phenomenon as Steve. The first scientific publication on subject suggests that Steve associated with an intense subauroral ion drift (SAID). However, additional inquiry warranted this suggested relationship it based a single case study. Here we present eight occurrences of coincident or near‐coincident measurements from European Space Agency's Swarm satellites and show consistently SAID. When satellite observations are compared to typical...
Abstract There has been an exciting recent development in auroral research associated with the discovery of a new subauroral phenomenon called STEVE (Strong Thermal Emission Velocity Enhancement). Although documented by amateur night sky watchers for decades, it is as yet unidentified upper atmosphere phenomenon. Observed first photographers, appears narrow luminous structure across over thousands kilometers east‐west direction. In this paper, we present statistical analysis properties 28...
Abstract So‐called “Steve” subauroral purple emissions have recently been uncovered by auroral photographers and rapidly become an intense subject of debate as to their origin. In some events, nearby periodic green also given the name “picket fence,” owing appearance. The present paper advances our understanding these phenomena narrowing down altitude extent Steve picket fence emissions. Our determination is based on event 16 September 2017, which was simultaneously observed from two vantage...
Abstract The magnetospheric driver of strong thermal emission velocity enhancement (STEVE) is investigated using conjugate observations when Van Allen Probes' footprint directly crossed both STEVE and stable red aurora (SAR) arc. In the ionosphere, associated with subauroral ion drift features, including electron temperature peak, density gradient, westward flow. SAR arc at lower latitudes corresponds to regions inside plasmapause isotropic plasma heating, which causes redline‐only via heat...
On the value of Hairs, as a Character in determining Limits subordinate Groups Species, considered connexion with Genera Eurybia (Cass.) and Olearia (Mönch), Compositæ Get access William Archer, Esq., F.L.S. Search for other works by this author on: Oxford Academic Google Scholar Botanical Journal Linnean Society, Volume 5, Issue 17, June 1860, Pages 17–25, https://doi.org/10.1111/j.1095-8312.1860.tb01033.x Published: 06 January 2009
Abstract Omega bands are curved aurora forms that evolve from a quiet arc located along the poleward edge of diffuse auroral band within midnight to morningside oval. They usually propagate eastward. Because omega significant contributor an active magnetotail, knowledge about their generation is important for understanding tail dynamics. Previous studies have shown streamers, footprints fast flows in tail, can into bands. Such events, however, limited, and it still unclear whether how...
Abstract Intense zonal ion velocity jets in the northern nightside auroral zone are measured during quiet geomagnetic conditions by Swarm satellites around 500 km altitude. These jets, exceeding 1 km/s over 50% of orbits measured, range from 20 to 100 meridional thickness and reach a maximum at boundary between upward downward field‐aligned current. On average they represent potential difference approximately 3 kV R1/R2 currents. This also separates different regions electron temperature...
Abstract Large thermospheric neutral density enhancements in the cusp region have been examined for many years. The Challenging Minisatellite Payload (CHAMP) satellite example has enabled observations of perturbation, showing that it is mesoscale size and exists statistically over solar cycle timescales. Further studies examining relationship with magnetospheric energy input shown fine‐scale Poynting fluxes are associated perturbations on a case‐by‐case basis, whilst others found downward...
Abstract The Swarm satellites observe strongly anisotropic ion temperatures at 500 km altitude. temperature anisotropy ratios going up to 5 for the strongest electric fields presented in this paper. largest observed exceed values predicted by theories of collisional heating strong flows a factor 2, indicating that cross sections should perhaps be revised O + colliding with O. Temperature is also found not simple function field strength. This could understood terms time delay needed advect...
Abstract We show the first ionospheric Hall and Pedersen conductances derived from Swarm magnetic electric field measurements during a crossing of morning sector auroral arc. Only Swarm‐A was used, with assumptions negligible azimuthal gradients vanishing eastward field. find upward field‐aligned current, enhanced conductances, relatively weak coincident Poleward arc, current downward, lower, enhanced. The arc embedded in westward electrojet, immediately equatorward peak density. portion...
Abstract The Swarm satellites regularly observe latitudinally narrow ion velocity jets exceeding 1 km/s relative to the surrounding plasma at high latitude. Two distinct categories of duskward directed flow channels are observed. most common situated between Region and 2 currents, observed primarily during quiet geomagnetic conditions, called Birkeland current boundary flows. During active a second type jet is equatorward edge colocated with sharp poleward density gradient, consistent...
Scanning electron microscopy and light histology were used to reveal the changes in overall morphology stem cell differentiation distribution that occur as a free-swimming, solid hydrozoan planula larva is transformed into sessile, hollow adult polyp. Eight stages of development are described: young 10-hour planula, mature 48-hour attaching disc, pawn, crown, immature polyp, primary The larval interstitial population (interstitial cells, nematocytes, ganglion cells) undergoes dramatic during...
ABSTRACT On a former occasion,2 I brought before the notice of those interested in types existence so lowly, series forms certain groups Rhizopoda, at once novel to our freshwaters, as well some them possessing themselves considerable interest connecting links, leading on their more complex and structurally differentiated marine relatives. Having, since then, continued bestow attention subject, venture propose bring forward from time time, opportunity may offer, such casual jottings, or...
When CHO cells are arrested in S-phase, they undergo repeated rounds of centrosome duplication without cell-cycle progression. While the increase is slow and asynchronous, number centrosomes these does rise with time. To investigate mechanisms controlling this duplication, we have S-phase for up to 72 h, coordinately inhibited new centriole formation by treatment microtubule poison colcemid. We find that such cells, pre-existing remain, a variable foci--containing alpha/gamma-tubulin centrin...
ABSTRACT THE discovery in Ireland of the very interesting and beautiful apparently rare organism, Stephanosphcera pluvialis (Cohn), would itself alone be worthy a record ‘Proceedings’ this society. But inasmuch as, whilst I had supply “Volvocine” my possession, remarkable phase or condition its history—so far as am aware, not before observed form, though without parallels elsewhere—presented to notice, value that becomes thereby so enhanced.
JOURNAL ARTICLE| 01 July 1864 Original Communications: Description of two new species Cosmarium (Corda) Penium (Bréb.) and Arthrodesmus (Ehr.) WILLIAM ARCHER Search for other works by this author on: This site PubMed Google Scholar Author article information Online Issn: 1477-9137 Print 0021-9533 Copyright © the Company Biologists Ltd.1864 J Cell Sci (1864) s2-4 (15): 174–182. https://doi.org/10.1242/jcs.s2-4.15.174 Views Icon Article contents Figures & tables Video Audio Supplementary Data...
ABSTRACT (Read before the Natural History Society of Dublin, Friday Evening, February 3, 1860; extracted from ‘Natural Review and Quarterly Journal Science,’ for July, 1860.)
An indepth three-dimensional investigation examined the surface morphological changes associated with development of a typical marine hydrozoan early cleavage embryo into mature planula larva. During embryogenesis arrangement and distribution microvilli change; cilia some epitheliomuscle cells appear before embryos gastrulate; undergoes dramatic in body shape. Early cleaving are bizarre morphology, however, by end late have rounded to form sphere. Gastrulation is characterized appearance...
Earth and Space Science Open Archive This work has been accepted for publication in Journal of Geophysical Research - Physics. Version RecordESSOAr is a venue early communication or feedback before peer review. Data may be preliminary. Learn more about preprints. preprintOpen AccessYou are viewing the latest version by default [v1]The Relationship Between Large Scale Thermospheric Density Enhancements Spatial Distribution Poynting FluxAuthorsDaniel DBillettiDGareth WilliamPerryiDLasse Boy...