A5102008396- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Icing and De-icing Technologies
- Cryospheric studies and observations
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Diverticular Disease and Complications
- Pluripotent Stem Cells Research
- Electroconvulsive Therapy Studies
- Smart Materials for Construction
- Surface Modification and Superhydrophobicity
- Treatment of Major Depression
- CRISPR and Genetic Engineering
- Magnetic confinement fusion research
- Global Energy and Sustainability Research
- Atmospheric aerosols and clouds
- Tissue Engineering and Regenerative Medicine
- Geothermal Energy Systems and Applications
- Lightning and Electromagnetic Phenomena
- earthquake and tectonic studies
- Esophageal and GI Pathology
Western General Hospital
2007-2021
University of Colorado Boulder
2006-2020
University of Edinburgh
2020
Cooperative Institute for Research in Environmental Sciences
2008-2020
NHS Lothian
2006-2019
University of Pennsylvania
2019
National Oceanic and Atmospheric Administration
2004-2017
Mersey Care NHS Trust
1997-2015
Memorial Sloan Kettering Cancer Center
2015
University of Colorado System
2011-2014
The Earth's thermosphere and ionosphere constitute a dynamic system that varies daily in response to energy inputs from above below. This can exhibit significant within an hour changes those inputs, as plasma fluid processes compete control its temperature, composition, structure. Within this system, short wavelength solar radiation charged particles the magnetosphere deposit energy, waves propagating lower atmosphere dissipate. Understanding global-scale of thermosphere-ionosphere (T-I)...
The ionosphere is a highly dynamic medium that exhibits weather disturbances at all latitudes, longitudes, and altitudes, these can have detrimental effects on both military civilian systems. In an effort to mitigate the adverse effects, we are developing physics‐based data assimilation model of neutral atmosphere called Global Assimilation Ionospheric Measurements (GAIM). GAIM will use ionosphere‐plasmasphere Kalman filter as basis for assimilating diverse set real‐time (or near real‐time)...
The daytime equatorial electrojet is a narrow band of enhanced eastward current flowing in the 100 to 120 km altitude region within ±2° latitude dip equator. A unique way determining strength observe difference magnitudes Horizontal (H) component between magnetometer placed directly on magnetic equator and one displaced 6 9 degrees away. these measured H values provides direct measure current, turn, magnitude vertical ExB drift velocity F ionosphere. This paper discusses recent study that...
Abstract Although all human ESC (hESC) lines have similar morphology, express key pluripotency markers, and can differentiate toward primitive germ layers in vitro, the lineage-specific developmental potential may vary between individual lines. In current study, four hESC were cultured same feeder-free conditions to provide a standardized platform for interline analysis. A high-throughput, forced-aggregation system involving centrifugation of defined numbers hESCs V-96 plates (V-96FA) was...
We describe a parameterized ionospheric model (PIM), global of theoretical climatology based on diurnally reproducible runs four physics numerical models the ionosphere. The models, taken together, cover E and F layers for all latitudes, longitudes, local times. PIM consists semianalytic representation these low, moderate, high levels both solar geomagnetic activity June December solstice March equinox conditions. produces output in several user selectable formats including or regional...
“SuomiNet,” a university-based, real-time, national Global Positioning System (GPS) network, is being developed for atmospheric research and education with funding from the National Science Foundation cost share collaborating universities. The named to honor meteorological satellite pioneer Verner Suomi, will exploit recently shown ability of ground-based GPS receivers make thousands accurate upper- lower-atmospheric measurements per day. Phase delays induced in signals by ionosphere neutral...
To realize the full scientific and clinical potential of human embryonic stem cell (hESC)-cardiomyocytes, strategies to overcome high degree heterogeneity differentiated populations are required. Here we demonstrate utility two transgenic approaches in enrichment cardiomyocytes derived from HUES-7 cells: (i) negative selection proliferating cells with herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) suicide gene system; (ii) positive expressing a bicistronic reporter [green...
The daytime equatorial electrojet is a narrow band of enhanced eastward current flowing in the 100–120 km altitude region within ±2° latitude dip equator. A unique way determining strength to observe difference magnitudes horizontal ( H ) component between magnetometer placed directly on magnetic equator and one displaced 6°–9° away. these measured values provides direct measure and, turn, magnitude vertical E × B drift velocity F ionosphere. This paper discusses recent study where 27 months...
Large-scale manufacture of human embryonic stem cells (hESCs) is prerequisite to their widespread use in biomedical applications. However, current hESC culture strategies are labor-intensive and employ highly variable processes, presenting challenges for scaled production commercial development. Here we demonstrate that passaging the lines, HUES7, NOTT1, with trypsin feeder-free conditions, compatible complete automation on CompacT SelecT, a commercially available industrially relevant...
Abstract The NASA Global‐scale Observations of the Limb and Disk (GOLD) mission has flown an ultraviolet‐imaging spectrograph on SES‐14, a communications satellite in geostationary orbit at 47.5°W longitude. That instrument observes Earth's far ultraviolet (FUV) airglow ~134–162 nm using two identical channels. observations performed include limb scans, stellar occultations, images sunlit nightside disk from 6:10 to 00:40 universal time each day. Initial analyses reveal interesting...
Abstract The National Aeronautics and Space Administration Global‐scale Observations of the Limb Disk ultraviolet spectrograph has been imaging equatorial ionization anomaly (EIA), regions ionosphere with enhanced electron density north south magnetic equator, since October 2018. initial 3 months observations was during solar minimum conditions, they included in December solstice unanticipated variability depleted regions. Depletions are seen on most nights, contrast to expectations from...
Since current empirical models specifying low‐latitude electron density profiles severely underestimate the daytime plasma scale‐height and total content (TEC) values, a semi‐empirical ionospheric model (SLIM) has been developed which is not only computationally fast, but also more realistic. Electron (180–1800 km) are theoretically calculated as function of latitude (every 2° between 24°N 24°S dip latitude) local time half hour, over 24 hours LT) by solving time‐dependent continuity...
Coherent and incoherent ground‐based radar measurements of the winter polar cap ionosphere at Thule Sondrestrom, Greenland have established existence “patches” enhanced ionization which drift across in an antisunward, noon‐midnight direction. Associated with these patches is strong radio scintillation activity severely disrupts ground‐to‐satellite communication systems interferes operation space surveillance high latitudes. Several recent studies shown that source sunlit subcusp rather than...
An investigation of the polar cap ionosphere near peak last solar cycle identified F layer arcs and ionization patches as unique features ionosphere, sources severe scintillations observed on 250‐MHz satellite beacon signals. The continuing investigations in January December 1983 1984 have shown that persist dominant winter during periods low sunspot numbers. Improved ionospheric soundings made at Thule, Greenland (86°CGL), showed a clear diurnal variation for occurrence patch‐type...
Creation of polar cap F ‐region patches are simulated for the first time using two independent physical models high latitude ionosphere. The patch formation is achieved by temporally varying magnetospheric electric field (ionospheric convection) input to models. imposed convection variations comparable changes in that result from B y IMF component southward interplanetary magnetic (IMF). Solar maximum‐winter simulations show simple pattern lead significant plasma structuring. Specifically,...
Depleted plasma regions in the equatorial ionosphere and their associated motions have been observed by a variety of ground‐based, rocket‐borne, satellite instruments. Various theories, based primarily on Rayleigh‐Taylor instability mechanism, proposed for formation motion these bubbles. Numerical studies past incorporated local electron density depletions, with Pedersen conductivities involving ion‐neutral collision frequencies. Realizing that bubbles are actually depleted magnetic flux...
Model studies have been carried out to specify the ionospheric conditions and electrodynamical processes required describe geometry of westward tilting bifurcating equatorial plasma depletions inferred from airglow imaging measurements taken on Ascension Island in early 1981. The results indicate that if tilts are be associated with eastward drifts decrease altitude above F peak, this shear must set up by a zonal wind pattern decreasing speed at increasing distances equator. Below...
Prompt daytime ionospheric responses are presented for the following four intense geomagnetic storms: 29 October 2003, 30 20 November and 7 2004. We perform a superposed epoch analysis of storms by defining start time when Kan‐Lee interplanetary electric field (proportional to reconnection field) first reaches 10 mV/m during period continuously southward B z . Measurements from GPS receiver onboard CHAMP satellite at 400 km altitude indicate significant low‐ middle‐latitude total electron...
Objective quantification of model performance based on metrics helps us evaluate the current state space physics modeling capability, address differences among various approaches, and track improvements over time. The Coupling, Energetics, Dynamics Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy ionosphere/thermosphere models reproducing ionosphere thermosphere parameters. A total nine events five physical...
The Whole Atmospheric Model (WAM) initialized with a data assimilation scheme is capable of simulating real sudden stratospheric warming (SSW) events. electrodynamics in the Coupled Thermosphere Ionosphere and Plasmasphere Electrodynamics model (CTIPe) was driven by WAM thermospheric winds January 2009 to study response ionospheric drifts during SSW. Simulation results are compared observations vertical drift at Jicamarca equatorial electrojet (EEJ) Asian sectors. Early morning upward...
Abstract Objective To develop a guideline for the primary care management of depression in later life based on best practice. Method Source material included relevant guidelines, literature reviews and consensus documents coupled with an updated review covering 1998–October, 2001. This was summarised as series evidence‐based statements recommendations agreed by consensus. Results Good quality evidence exists pharmacological psychological treatment depressive episode (major depression),...