scholarly journals Time-dependent responses of the neutral mass density to magnetospheric energy inputs into the cusp region in the thermosphere: A high-resolution two-dimensional local modeling

2020 ◽  
Author(s):  
Tomokazu Oigawa ◽  
Hiroyuki Shinagawa ◽  
Satochi Taguchi
Keyword(s):  
High Resolution ◽  
Electric Fields ◽  
Mass Density ◽  
Satellite Observation ◽  
Two Dimensional ◽  
Additional Energy ◽  
Champ Satellite ◽  
Cusp Region ◽  
Energy Inputs ◽  
Density Enhancement

Abstract Remarkable enhancements of the thermospheric mass density around the 400-km altitude in the cusp region have been observed by the CHAllenging Minisatellite Payload (CHAMP) satellite. We employed a high-resolution two-dimensional local model to gain insights into the extent to which the neutral-ion drag process controls the mass density’s enhancements under the energy inputs typical of the cusp. We expressed those energy inputs by quasi-static electric fields and electron precipitation. We compared two cases and calculated the thermospheric dynamics with and without neutral-ion drags. We found that in the more realistic case containing the neutral-ion drag, the calculated mass density enhancement was 10% at most, which is dramatically smaller than the observations by the CHAMP satellite (33% on average). The results also showed that the neutral-ion drag process suppresses Joule heating and neutral mass density enhancements, as well as the chemical reaction process. The discrepancy between our modeling result and the satellite observation suggests the existence of additional energy sources, such as Alfvén waves propagating from the magnetosphere, which play an important role in the cusp’s density enhancement.

Large scale thermospheric density enhancements in relation to downward Poynting fluxes: Statistics from CHAMP, AMPERE and SuperDARN

2021 ◽  
Author(s):  
Daniel Billett ◽  
Gareth Perry ◽  
Lasse Clausen ◽  
William Archer ◽  
Kathryn McWilliams ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Mass Density ◽  
Global Scale ◽  
Champ Satellite ◽  
Poynting Flux ◽  
Cusp Region ◽  
F Region ◽  
Primary Driver ◽  
Density Perturbations

<p>Large thermospheric neutral density enhancements in the cusp region have been examined for many years. The CHAMP satellite for example has enabled many observations of the perturbation, showing that it is mesoscale in size and exists on statistical timescales. Further studies examining the relationship with magnetospheric energy input have shown that fine-scale Poynting fluxes are associated with the density perturbations on a case-by-case basis, whilst others have found that mesoscale downward fluxes also exist in the cusp region statistically.</p><p>In this study, we use nearly 8 years of the overlapping SuperDARN and AMPERE datasets to generate global-scale patterns of the high-latitude and height-integrated Poynting flux into the ionosphere, with a time resolution of two minutes. From these, average patterns are generated based on the IMF orientation. We show the cusp is indeed an important feature in the Poynting flux maps, but the magnitude does not correlate well with statistical neutral mass density perturbations observed by the CHAMP satellite on similar spatial scales. Mesoscale height-integrated Poynting fluxes thus cannot fully account for the cusp neutral mass density enhancement, meaning energy deposition in the F-region or on fine-scales, which is not captured by our analysis, could be the primary driver.</p>

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

High resolution two-dimensional motility mapping; Methodology and initial results

2001 ◽  
Vol 120 (5) ◽  
pp. A226-A226 ◽  
Author(s):  
W LAMMERS ◽  
S DHANASEKARAN ◽  
J SLACK ◽  
B STEPHEN
Keyword(s):  
High Resolution ◽  
Two Dimensional ◽  
Initial Results

Diversity of Glycoprotein Deficiencies in Glanzmann’s Thrombasthenia

1985 ◽  
Vol 54 (03) ◽  
pp. 626-629 ◽  
Author(s):  
M Meyer ◽  
F H Herrmann
Keyword(s):  
High Resolution ◽  
Gel Electrophoresis ◽  
Type Ii ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Structural Variant ◽  
Glanzmann’S Thrombasthenia ◽  
Crossed Immunoelectrophoresis ◽  
Glanzmann's Thrombasthenia ◽  
Platelet Proteins

SummaryThe platelet proteins of 9 thrombasthenic patients from 7 families were analysed by high resolution two-dimensional gel electrophoresis (HR-2DE) and crossed immunoelectrophoresis (CIE). In 7 patients both glycoproteins (GPs) IIb and Ilia were absent or reduced to roughly the same extent. In two related patients only a trace of GP Ilb-IIIa complex was detected in CIE, but HR-2DE revealed a glycopeptide in the position of GP Ilia in an amount comparable to type II thrombasthenia. This GP Ilia-like component was neither recognized normally by anti-GP Ilb-IIIa antibodies nor labeled by surface iodination. In unreduced-reduced two-dimensional gel electrophoresis two components were observed in the region of GP Ilia. The assumption of a structural variant of GP Ilia in the two related patients is discussed.

Agriculture—Things That Are Grown

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Crop Yields ◽  
Animal Feed ◽  
Electrical Power ◽  
Construction Materials ◽  
Embodied Energy ◽  
Liquid Fuels ◽  
Energy Output ◽  
Recycled Paper ◽  
Additional Energy ◽  
Energy Inputs

Timber has the lowest embodied energy of any of the construction materials. Paper production from trees requires much more energy. There is some energy saving in recycling, as recycled paper substitutes for pulp derived from wood chips. Growing crops for food also requires energy. The energy required for plants to grow comes from the sun, but there are additional energy inputs from fertiliser and farm machinery to speed up the growth process and vastly improve crop yields. If grains are used as animal feed, then the energy inputs are much larger than the dietary energy output—the larger the animal and the longer it is fattened up before slaughter, the more inefficient the process. The use of crops to make fuel for electrical power generation or for processing into liquid fuels is horribly inefficient. The problem is simple—the plants do not grow fast enough!

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