132 research outputs found
Thermospheric poleward wind surge at midlatitudes during great storm intervals
We report a significant poleward surge in thermospheric winds at subauroral and midlatitudes following the 17–18 March 2015 great geomagnetic storm. This premidnight surge is preceded by strong westward winds. These disturbances were observed over three sites with geodetic latitudes 35–42°N in the American sector by Fabry-Perot interferometers at 630 nm wavelength. Prior to the wind disturbances, subauroral polarization streams (SAPS) were measured by the Millstone Hill incoherent scatter radar between 20 and 02 UT. We identify the observed neutral wind variations as driven by SAPS, through a scenario where strong ion flows cause a westward neutral wind, subsequently establishing a poleward wind surge due to the poleward Coriolis force on that westward wind. These regional disturbances appear to have prevented the well-known storm time equatorward wind surge from propagating into low latitudes, with the consequence that the classic disturbance dynamo mechanism failed to occur.United States. National Aeronautics and Space Administration (Living with a Star NNX15AB83G
Cedar 88
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94656/1/eost7523.pd
Measured response of the equatorial thermospheric temperature to geomagnetic activity and solar flux changes
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95228/1/grl2892.pd
Equatorial airglow depletions induced by thermospheric winds
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95355/1/grl2948.pd
Mapping the wind in the polar thermosphere a case study within the CEDAR Program
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95064/1/eost7749.pd
Cardiometabolic results from an armband-based weight loss trial
Purpose: This report examines the blood chemistry and blood pressure (BP) results from the Lifestyle Education for Activity and Nutrition (LEAN) study, a randomized weight loss trial. A primary purpose of the study was to evaluate the effects of real-time self-monitoring of energy balance (using the SenseWearTM Armband, BodyMedia, Inc Pittsburgh, PA) on these health factors.
Methods: 164 sedentary overweight or obese adults (46.8 ± 10.8 years; BMI 33.3 ± 5.2 kg/m2; 80% women) took part in the 9-month study. Participants were randomized into 4 conditions: a standard care condition with an evidence-based weight loss manual (n = 40), a group-based behavioral weight loss program (n = 44), and armband alone condition (n = 41), and a group plus armband (n = 39) condition. BP, fasting blood lipids and glucose were measured at baseline and 9 months.
Results: 99 participants (60%) completed both baseline and follow-up measurements for BP and blood chemistry analysis. Missing data were handled by baseline carried forward. None of the intervention groups had significant changes in blood lipids or BP when compared to standard care after adjustment for covariates, though within-group lowering was found for systolic BP in group and group + armband conditions, a rise in total cholesterol and LDL were found in standard care and group conditions, and a lowering of triglycerides was found in the two armband conditions. Compared with the standard care condition, fasting glucose decreased significantly for participants in the group, armband, and group + armband conditions (all P \u3c 0.05), respectively.
Conclusion: Our results suggest that using an armband program is an effective strategy to decrease fasting blood glucose. This indicates that devices, such as the armband, can be a successful way to disseminate programs that can improve health risk factors. This can be accomplished without group-based behavioral programs, thereby potentially reducing costs
The \u3ci\u3eDrosophila\u3c/i\u3e T-box Transcription Factor Midline Functions Within the Notch-Delta Signaling Pathway To Specify Sensory Organ Precursor Cell Fates and Regulates Cell Survival Within the Eye Imaginal Disc
We report that the T-box transcription factor Midline (Mid), an evolutionary conserved homolog of the vertebrate Tbx20 protein, functions within the Notch-Delta signaling pathway essential for specifying the fates of sensory organ precursor (SOP) cells. These findings complement an established history of research showing that Mid regulates the cell-fate specification of diverse cell types within the developing heart, epidermis and central nervous system. Tbx20 has been detected in unique neuronal and epithelial cells of embryonic eye tissues in both mice and humans. However, the mechanisms by which either Mid or Tbx20 function to regulate cell-fate specification or other critical aspects of eye development including cell survival have not yet been elucidated. We have also gathered preliminary evidence suggesting that Mid may play an indirect, but vital role in selecting SOP cells within the third-instar larval eye disc by regulating the expression of the proneural gene atonal. During subsequent pupal stages, Mid specifies SOP cell fates as a member of the Notch-Delta signaling hierarchy and is essential for maintaining cell viability by inhibiting apoptotic pathways. We present several new hypotheses that seek to understand the role of Mid in regulating developmental processes downstream of the Notch receptor that are critical for specifying unique cell fates, patterning the adult eye and maintaining cellular homeostasis during eye disc morphogenesis. © 2013 Elsevier Ireland Ltd
Hierarchical Multigrid Ansatz for Variational Quantum Algorithms
Quantum computing is an emerging topic in engineering that promises to enhance supercomputing using fundamental physics. In the near term, the best candidate algorithms for achieving this advantage are variational quantum algorithms (VQAs). We design and numerically evaluate a novel ansatz for VQAs, focusing in particular on the variational quantum eigensolver (VQE). As our ansatz is inspired by classical multigrid hierarchy methods, we call it multigrid ansatz. The multigrid ansatz creates a parameterized quantum circuit for a quantum problem on qubits by successively building and optimizing circuits for smaller qubit counts , reusing optimized parameter values as initial solutions to next level hierarchy at . We show through numerical simulation that the multigrid ansatz outperforms the standard hardware-efficient ansatz in terms of solution quality for the Laplacian eigensolver as well as for a large class of combinatorial optimization problems with specific examples for MaxCut and Maximum -Satisfiability. Our studies establish the multi-grid ansatz as a viable candidate for many VQAs and in particular present a promising alternative to the QAOA approach for combinatorial optimization problems.11 pages, 9 figure
Effects of the midnight temperature maximum observed in the thermosphere–ionosphere over the northeast of Brazil
Science highlights from the Kjell Henriksen Observatory on Svalbard
The Kjell Henriksen Observatory (KHO) is the world’s largest optical observatory for auroral and airglow measurements, operated by the University Centre in Svalbard (UNIS). KHO is a unique site that lies underneath the dayside cusp, a funnel-shaped region where particles from the Sun can directly enter the Earth’s upper atmosphere, including the ionosphere. Building on the pioneering observations of its predecessor—the Auroral Station in Adventdalen, Svalbard—KHO has played a pivotal role in advancing our understanding of phenomena in the polar atmosphere. The Auroral Station and KHO have amassed climatological measurements over Svalbard for an impressive 40-year period. KHO’s diverse instrumentation, combined with other co-located optical and radar infrastructure, and in situ measurements from satellites and sounding rockets, has paved the way for impactful multi-instrument studies. Serving as an accessible testbed for instrument development, new types of instruments have recently been installed, both at KHO and on satellites. Beyond its scientific contributions, KHO has become an integral part of the Longyearbyen community, with students, visitors, and locals participating in tours and educational initiatives. This connection underscores KHO’s multi-functional role, not only as a centre for excellent research but also as a vital hub for public outreach and engagement
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