On the 3D Solar Corona Structure

1994 ◽  
Vol 144 ◽  
pp. 585-588
Author(s):  
S. Koutchmy ◽  
M. M. Molodensky ◽  
J.-C. Vial
Keyword(s):  
Solar Corona ◽  
Current Sheet ◽  
3D Structure ◽  
Simple Analysis ◽  
Eclipse Observations ◽  
Analysis Of Results ◽  
True Position ◽  
Corona Structure ◽  
First Time ◽  
Coronal Structures

AbstractWe consider the 3D structure of the solar corona using eclipse observations. We use a pseudostereoscopic effect of the rigidly rotating corona to determine the true position of the main coronal structures: broad threads, rays and streamers. We find that observations collected by the “Multi-station International Coronal Experiment” are well suited for solving this problem. Formula and error estimation are given to demonstrate the feasibility of the method. An example of stereo-view deduced from a simple analysis of results coming from the 1991 eclipse is given. The observed apparent shifts allow for the first time to apprehend the true 3D structure of the corona. The structure of streamers was compared with the pecularities (pleats and cusps) of the solar heliosphere current sheet, deduced from the sourse surface. The positions of the two main streamers systems rays (near the N-E and S-limb) coincide with the pleats of the current heliosphere layer. We conclude that large helmet streamers are composed by the pleats of the heliosphere current sheet projected on the plane of the sky.

Phenomenological Pattern of the Outer Solar Corona Structure

1994 ◽  
Vol 144 ◽  
pp. 115-117
Author(s):  
R. A. Gulyaev
Keyword(s):  
Solar Corona ◽  
Current Sheet ◽  
3D Structure ◽  
Heliospheric Current Sheet ◽  
Hyperbolic Paraboloid ◽  
Corona Structure ◽  
Outer Corona ◽  
Second Degree

AbstractTopology of the outer solar corona has been analysed. In doing so the outer corona is treated as a visible manifestation of the heliospheric current sheet base. Generalization of the recent conception of the flat (galaxy-like) solar corona has been suggested. It is shown that 3D structure of the outer corona is well fitted by a second-degree surface of a hyperbolic paraboloid.

Flaring Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 227-234
Author(s):  
T. Watanabe
Keyword(s):  
Solar Corona ◽  
Magnetic Reconnection ◽  
Time Scales ◽  
Solar Flares ◽  
Initial Phase ◽  
X Ray ◽  
Ionized Plasmas ◽  
First Time ◽  
Coronal Structures

AbstractThe highlights of the Japanese solar mission,Yohkoh, are presented, with emphasis on flaring structures in the solar corona. Definitive evidences of the magnetic reconnection in the solar corona are observationally confirmed for the first time. New insights in the location of hard X-ray sources are obtained. Completely blueshifted line emissions from highly ionized plasmas are seen at the very initial phase of solar flares. It is revealed that the solar corona is very dynamic in various time scales in X-ray intensities. Ample evidences of numerous flare-like activity like microflares and X-ray jets conclude that they are also the manifestation of the magnetic reconnection.

Colour Photometry of the Solar Corona of July 11, 1991

1994 ◽  
Vol 144 ◽  
pp. 597-599 ◽  
Author(s):  
I. V. Alexeyeva ◽  
N. L. Kroussanova ◽  
M. V. Streltsova
Keyword(s):  
Solar Corona ◽  
Red Emission ◽  
Coronal Structures

AbstractThe results of photometry of colour positives of the solar corona of July 11, 1991 are presented. Observations of the white corona were made without radial niters in Jojutla (Mexico). Dependences of coronal brightness on distance in the red (640 nm) and blue (420 nm) wavelength intervals are deduced for different coronal structures up to 3.0-3.5R⊙. The effect of ”reddening“ is noted. The excess of the red emission to the blue one (I640nm/I420nm) is found to be 1.20 and 1.17 at distance of 2.2R⊙for the N-E helmet streamer (P ≃ 37°) and the N-W region of low brightness (P ≃ 339°), respectively.

Calculated Coronal Magnetic Fields and Their Comparison with the Coronal Structures as Observed during Five Solar Eclipses

1994 ◽  
Vol 144 ◽  
pp. 559-564
Author(s):  
P. Ambrož ◽  
J. Sýkora
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Coronal Magnetic Field ◽  
Coronal Magnetic Fields ◽  
Solar Eclipses ◽  
Coronal Structures

AbstractWe were successful in observing the solar corona during five solar eclipses (1973-1991). For the eclipse days the coronal magnetic field was calculated by extrapolation from the photosphere. Comparison of the observed and calculated coronal structures is carried out and some peculiarities of this comparison, related to the different phases of the solar cycle, are presented.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Exploring Coronal Structures with SOHO

2000 ◽  
Vol 179 ◽  
pp. 403-406
Author(s):  
M. Karovska ◽  
B. Wood ◽  
J. Chen ◽  
J. Cook ◽  
R. Howard
Keyword(s):  
Solar Corona ◽  
Image Enhancement ◽  
Coronal Mass Ejections ◽  
Dynamical Evolution ◽  
Small Scale ◽  
Low Contrast ◽  
Contrast Structures ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Coronal Structures

AbstractWe applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT.

scholarly journals Modeling and Molecular Dynamics of the 3D Structure of the HPV16 E7 Protein and Its Variants

2021 ◽  
Vol 22 (3) ◽  
pp. 1400
Author(s):  
Ciresthel Bello-Rios ◽  
Sarita Montaño ◽  
Olga Lilia Garibay-Cerdenares ◽  
Lilian Esmeralda Araujo-Arcos ◽  
Marco Antonio Leyva-Vázquez ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
3D Structure ◽  
Epidemiological Studies ◽  
Dynamics Simulation ◽  
Structural Refinement ◽  
Oncogenic Potential ◽  
Structural Differences ◽  
Reference Protein ◽  
E6 And E7 ◽  
First Time

The oncogenic potential of high-risk human papillomavirus (HPV) is predicated on the production of the E6 and E7 oncoproteins, which are responsible for disrupting the control of the cell cycle. Epidemiological studies have proposed that the presence of the N29S and H51N variants of the HPV16 E7 protein is significantly associated with cervical cancer. It has been suggested that changes in the amino acid sequence of E7 variants may affect the oncoprotein 3D structure; however, this remains uncertain. An analysis of the structural differences of the HPV16 E7 protein and its variants (N29S and H51N) was performed through homology modeling and structural refinement by molecular dynamics simulation. We propose, for the first time, a 3D structure of the E7 reference protein and two of Its variants (N29S and H51N), and conclude that the mutations induced by the variants in N29S and H51N have a significant influence on the 3D structure of the E7 protein of HPV16, which could be related to the oncogenic capacity of this protein.

PUBLIC HEALTH, NURSING, MEDICAL SOCIAL WORK

PEDIATRICS ◽  
1956 ◽  
Vol 17 (1) ◽  
pp. 116-120
Keyword(s):  
Birth Rate ◽  
Numerical Data ◽  
Vital Statistics ◽  
Monthly Variation ◽  
Medical Social Work ◽  
National Office ◽  
True Position ◽  
Low Levels ◽  
Health Nursing ◽  
First Time

THERE are presented herewith annual summaries of provisional vital statistics of the U.S.A. for 1954, as published by the National Office of Vital Statistics in Volume 3, Number 13, of the Monthly Vital statistics Report. These provisional figures are based on the data from monthly reports of certificates actually received in registration offices in the various states and cities. Previous experience shows that for the country as a whole these estimates will correspond very closely to the final rates when they are compiled. The provisional rates thus reflect the true position sufficiently well to allow their use for immediate planning purposes. Birth rates are shown in Figure 1, by monthly variation, comparing 1953 and 1954. Table 1 gives both numerical data and rates by the states in which the birth occurred. Information by place of residence, which is of course more significant, will be given in the final reports, which will be some time in appearing. In 1954 registered live births again reached an all time high, estimated at 4,021,000, compared to 3,909,000 in 1953. This is the fourth successive record-breaking year and the first time the registered number of births has surpassed 4 million. Predictions of several years ago that the birth rate would shortly begin dropping to the low levels of the 1930's were again proved wrong, for the estimated rate for 1954 was 25.0 per 1,000 population, as against a comparable figure of 24.7 in 1953.

scholarly journals Magnetically Driven Motions in Solar Corona

1980 ◽  
Vol 91 ◽  
pp. 487-489 ◽  
Author(s):  
B. V. Somov ◽  
S. I. Syrovatskii
Keyword(s):  
Magnetic Field ◽  
Solar Corona ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Magnetic Dipole ◽  
Plasma Flow ◽  
Strong Field ◽  
Plasma Velocity ◽  
Rapid Process

Solution of the nonlinear MHD problem of plasma flow in an increasing dipolar magnetic field is obtained in the approximation of a strong field. The distributions of plasma velocity, displacement, and density are calculated. The situation when the magnetic dipole is ‘increased’ by rapid process of magnetic reconnection or current sheet rupture is illustrated. Possible applications are discussed in connection with plasma ejections from chromosphere in corona.

scholarly journals Rindera graeca (Boraginaceae) Phytochemical Profile and Biological Activities

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3625
Author(s):  
Christos Ganos ◽  
Nektarios Aligiannis ◽  
Ioanna Chinou ◽  
Nikolaos Naziris ◽  
Maria Chountoulesi ◽  
...  
Keyword(s):  
Free Radical ◽  
Biological Activities ◽  
Biological Membrane ◽  
3D Structure ◽  
Total Phenolic ◽  
Phytochemical Analysis ◽  
Endemic Plant ◽  
Aerial Parts ◽  
Potential Applications ◽  
First Time

Rindera graeca is a Greek endemic plant of the Boraginaceae family which has never been studied before. Consequently, this study attempted to phytochemically examine the aerial parts of this species. Nine phenolic secondary metabolites were identified, consisting of seven caffeic acid derivatives and two flavonol glucosides, namely rutin and quercetin-3-rutinoside-7-rhamnoside. These flavonoids, together with rosmarinic acid, were isolated via column chromatography and structurally determined through spectral analysis. Quercetin-3-rutinoside-7-rhamnoside is an unusual triglycoside, which is identified for the first time in Rindera genus and among Boraginaceae plants. This metabolite was further examined with thermal analysis and its 3D structure was simulated, revealing some intriguing information on its interaction with biological membrane models, which might have potential applications in microcirculation-related conditions. R. graeca was also analyzed for its pyrrolizidine alkaloids content, and it was found to contain echinatine together with echinatine N-oxide and rinderine N-oxide. Additionally, the total phenolic and flavonoid contents of R. graeca methanol extract were determined, along with free radical inhibition assays. High total phenolic content and almost complete inhibition at experimental doses at the free radical assays indicate a potent antioxidant profile for this plant. Overall, through phytochemical analysis and biological activity assays, insight was gained on an endemic Greek species of the little-studied Rindera genus, while its potential for further applications has been assessed.

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