Solar rotation and the giant cells

Solar Physics ◽  
1987 ◽  
Vol 110 (1) ◽  
pp. 59-71 ◽  
Author(s):  
P. R. Wilson
Keyword(s):  
Solar Rotation ◽  
Giant Cells

scholarly journals Variability in the Power Spectrum of Solar Five-Minute Oscillations

1983 ◽  
Vol 66 ◽  
pp. 411-425
Author(s):  
Frank Hill ◽  
Juri Toomre ◽  
Laurence J. November
Keyword(s):  
Large Scale ◽  
Solar Rotation ◽  
Temporal Frequency ◽  
Power Spectra ◽  
Giant Cells ◽  
Spectral Lines ◽  
Data Sets ◽  
Data Set ◽  
Temporal Sampling ◽  
Velocity Changes

AbstractTwo-dimensional power spectra of solar five-minute oscillations display prominent ridge structures in (k, ω) space, where k is the horizontal wavenumber and ω is the temporal frequency. The positions of these ridges in k and ω can be used to probe temperature and velocity structures in the subphotosphere. We have been carrying out a continuing program of observations of five-minute oscillations with the diode array instrument on the vacuum tower telescope at Sacramento Peak Observatory (SPO). We have sought to establish whether power spectra taken on separate days show shifts in ridge locations; these may arise from different velocity and temperature patterns having been brought into our sampling region by solar rotation. Power spectra have been obtained for six days of observations of Doppler velocities using the Mg I λ5173 and Fe I λ5434 spectral lines. Each data set covers 8 to 11 hr in time and samples a region 256″ × 1024″ in spatial extent, with a spatial resolution of 2″ and temporal sampling of 65 s. We have detected shifts in ridge locations between certain data sets which are statistically significant. The character of these displacements when analyzed in terms of eastward and westward propagating waves implies that changes have occurred in both temperature and horizontal velocity fields underlying our observing window. We estimate the magnitude of the velocity changes to be on the order of 100 m s -1; we may be detecting the effects of large-scale convection akin to giant cells.

scholarly journals Global magnetic cycles in rapidly rotating younger suns

2010 ◽  
Vol 6 (S273) ◽  
pp. 272-275 ◽  
Author(s):  
Nicholas J. Nelson ◽  
Benjamin P. Brown ◽  
Matthew K. Browning ◽  
Allan Sacha Brun ◽  
Mark S. Miesch ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Solar Rotation ◽  
Giant Cells ◽  
Temporal Variations ◽  
Opposite Polarity ◽  
Magnetic Activity ◽  
Dynamo Action ◽  
Magnetic Buoyancy ◽  
Magnetic Cycles

AbstractObservations of sun-like stars rotating faster than our current sun tend to exhibit increased magnetic activity as well as magnetic cycles spanning multiple years. Using global simulations in spherical shells to study the coupling of large-scale convection, rotation, and magnetism in a younger sun, we have probed effects of rotation on stellar dynamos and the nature of magnetic cycles. Major 3-D MHD simulations carried out at three times the current solar rotation rate reveal hydromagnetic dynamo action that yields wreaths of strong toroidal magnetic field at low latitudes, often with opposite polarity in the two hemispheres. Our recent simulations have explored behavior in systems with considerably lower diffusivities, achieved with sub-grid scale models including a dynamic Smagorinsky treatment of unresolved turbulence. The lower diffusion promotes the generation of magnetic wreaths that undergo prominent temporal variations in field strength, exhibiting global magnetic cycles that involve polarity reversals. In our least diffusive simulation, we find that magnetic buoyancy coupled with advection by convective giant cells can lead to the rise of coherent loops of magnetic field toward the top of the simulated domain.

scholarly journals Search for Giant Cells in the Solar Convection Zone

1980 ◽  
Vol 91 ◽  
pp. 21-23 ◽  
Author(s):  
B. J. Labonte ◽  
R. Howard
Keyword(s):  
Large Scale ◽  
Convection Zone ◽  
Solar Rotation ◽  
Longitudinal Velocity ◽  
Giant Cells ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Mount Wilson Observatory ◽  
Entire Dataset ◽  
Full Disk

The Mount Wilson Observatory has obtained daily full disk digital magnetograms of the Sun since 1966, with 12 to 17 arcsecond resolution. As each magnetogram is taken, the position of the Doppler line shift compensator is also recorded, thus giving a full disk map of the longitudinal velocity. This entire dataset is currently being rereduced on a uniform basis (Howard et al., 1980), and daily arrays of residual velocities are being formed by removing large scale patterns, e.g., Earth's motions, solar rotation, limbshift. Data from the years 1972 through 1978 are used here.

Influence of Magnetic Fields on Solar Hydrodynamics: Experimental Results

1977 ◽  
Vol 36 ◽  
pp. 143-180 ◽  
Author(s):  
J.O. Stenflo
Keyword(s):  
Solar Activity ◽  
Energy Balance ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
General Problem ◽  
Solar Rotation ◽  
Active Regions ◽  
Physical Conditions ◽  
Dynamic Phenomena

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.

Studies of a Defective Measles Virus

1968 ◽  
Vol 26 ◽  
pp. 208-209
Author(s):  
R. M. McCombs ◽  
M. Benyesh-Melnick ◽  
J. P. Brunschwig
Keyword(s):  
Inclusion Bodies ◽  
Measles Virus ◽  
Giant Cells ◽  
Helical Structures ◽  
Thin Sections ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Culture Cells ◽  
Infected Cells ◽  
Eosinophilic Inclusions

Measles virus is an agent that is capable of replicating in a number of different culture cells and generally causes the formation of multinucleated giant cells. As a result of infection, virus is released from the cells into the culture fluids and reinfection can be initiated by this cell-free virus. The extracellular virus has been examined by negative staining with phosphotungstic acid and has been shown to be a rather pleomorphic particle with a diameter of about 140 mμ. However, no such virus particles have been detected in thin sections of the infected cells. Rather, the only virus-induced structures present in the giant cells are eosinophilic inclusions (intracytoplasmic or intranuclear). These inclusion bodies have been shown to contain helical structures, resembling the nucleocapsid observed in negatively stained preparations.

Cell-matrix interactions in the early mouse embryo

1992 ◽  
Vol 50 (1) ◽  
pp. 600-601
Author(s):  
A.E. Sutherland ◽  
P.G. Calarco ◽  
C.H. Damsky
Keyword(s):  
Mouse Embryo ◽  
Giant Cells ◽  
Blastocyst Stage ◽  
Integrin Subunit ◽  
Β1 Integrin ◽  
Cell Stage ◽  
Early Mouse Embryo ◽  
Migratory Activity ◽  
Early Mouse ◽  
Cell Matrix Interactions

Cell-extracellular matrix (ECM) interactions mediated by the integrin family of receptors are critical for morphogenesis and may also play a regulatory role in differentiation during early development. We have examined the onset of expression of individual integrin subunit proteins in the early mouse embryo, and their roles in early morphogenetic events. As detected by immunoprecipitation, the α6, αV, β1, and β3 subunits are detected as early as the 4-cell stage, α5 at the hatched blastocyst stage and αl and α3 following blastocyst attachment. We tested the role of these integrins in the attachment and migratory activity of two cell populations of the early mouse embryo: the trophoblast giant cells, which invade the uterine stroma and ultimately contribute to the chorio-allantoic placenta, and the parietal endoderm, which migrates over the inner surface of the trophoblast and ultimately forms Reichert's membrane and the parietal yolk sac. Experiments were done in serum-free medium on substrates coated with laminin (Ln) and fibronectin (Fn). Trophoblast outgrowth occurs on Ln and its E8 fragment (long arm), but not on the E1’ fragment (cross region) (Figs. 1, 2 ). This outgrowth is inhibited by anti-E8, anti-Ln, and by the anti-β1 family antiserum anti-ECMR, but not by anti-αV or the function-perturbing GoH3 antibody that recognizes the α6/β1 integrin, a major Ln (E8) receptor. This suggests that trophoblast outgrowth on Ln or E8 is mediated by a different β1 integrin such as α3/β1. Early stages of trophoblast outgrowth (up to 48 hours) on Fn are inhibited by anti-Fn and by function-perturbing anti-αV antibodies, whereas at later times outgrowth becomes insensitive to anti-αV but remains sensitive to the anti-β1 family antiserum anti-ECMr, indicating that trophoblast cells modulate their interaction with Fn during outgrowth. Trophoblast outgrowth on vitronectin (Vn) is sensitive to anti-αV antibodies throughout the 5-day period examined.

Histological verification of non-specific aorta-arteritis (Takayasu's arteritis) using percutaneous transluminal atherectomy

VASA ◽  
2004 ◽  
Vol 33 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Zeller ◽  
Koch ◽  
Frank ◽  
Bürgelin ◽  
Schwarzwälder ◽  
...  
Keyword(s):  
Clinical Diagnosis ◽  
Axillary Artery ◽  
Takayasu’S Arteritis ◽  
Giant Cells ◽  
Interventional Therapy ◽  
Takayasu's Arteritis ◽  
New Device ◽  
First Case ◽  
Anti Inflammatory ◽  
Percutaneous Transluminal

Diagnosis of non-specific aorto-arteritis (NSAA, Takaysu's arteritis) is typically based on clinical and investigational parameters. We report here about two patients with clinically suspected diagnosis of a Takayasu's arteritis already under anti-inflammatory therapy in whom percutaneous transluminal atherectomy of subclavian and axillary artery stenoses was performed to relief the patients from symptoms – intermittent dyspraxia of the arms – and to verify the clinical diagnosis by histology. In the first case aorto-arteritis could be histologically confirmed through the analysis of plaque material including media structures excised from the subclavian and axillary arteries using a new device for atherectomy. The biopsy showed diffuse inflammation and granulomatous lesions with giant cells typically for Takayasu's disease. In the second patient, biopsy showed no acute or chronic inflammatory signs but only atherosclerotic lesions. Percutaneous transluminal atherectomy is therefore not only an interventional but also a diagnostic tool and should be used in every case of interventional therapy of suspected aorto-arteritis to make the clinical diagnosis and as a major consequence the initiation of an aggressive anti-inflammatory medical therapy more reliable.

Pulmonary hair embolism in a rescued free-ranging Eurasian otter Lutra lutra in Kinmen, Taiwan

2020 ◽  
Vol 142 ◽  
pp. 55-61
Author(s):  
WT Li ◽  
YL Chiang ◽  
TY Chen ◽  
CL Lai
Keyword(s):  
Foreign Body ◽  
Traumatic Injury ◽  
Lung Parenchyma ◽  
Giant Cells ◽  
Hair Shaft ◽  
Lutra Lutra ◽  
Lung Lobe ◽  
Eurasian Otter ◽  
Foreign Body Giant Cells ◽  
Free Ranging

Eurasian otters Lutra lutra are listed as Near Threatened on the IUCN Red List and are imperiled by habitat loss, water pollution, and poaching. Harassment and attacks by stray animals are also recognized threats to the health of wild Eurasian otters. Pulmonary hair embolism is a possible complication in animals with deep traumatic injury, but to date no cases have been reported in wildlife. A free-ranging, adult male Eurasian otter was rescued due to severe emaciation and multiple bite wounds. The otter died 3 d after rescue and was necropsied. Grossly, a 1.5 × 1.5 × 1.5 cm firm nodule was observed in the left cranial lung lobe. Histologically, a fragment of hair shaft surrounded by multinucleated foreign body giant cells was observed in a medium-sized vein, and extensive eosinophilic infiltration was noted in the adjacent vascular wall and lung parenchyma. Based on the gross and histological findings, the pulmonary lesion was consistent with eosinophilic pneumonia and vasculitis induced by hair embolism. The presence of well-formed multinucleated foreign body giant cells and eosinophils may imply a late stage of foreign body reaction, and thus the presumptive source of hair embolism is an animal bite. This is the first report of pulmonary hair embolism associated with animal bite in a rescued free-ranging Eurasian otter.

Complications of systemic cytomegalovirus infection in therapy refracter Hodgkin’s lymphoma

2012 ◽  
Vol 153 (19) ◽  
pp. 751-755 ◽  
Author(s):  
Gábor Irsai ◽  
Tatjana Tampu-Kiss ◽  
Balázs Dezső ◽  
Zsófia Miltényi ◽  
Árpád Illés ◽  
...  
Keyword(s):  
Hodgkin's Disease ◽  
Tumor Invasion ◽  
Cytomegalovirus Infection ◽  
Hodgkin’S Disease ◽  
Fatal Outcome ◽  
Giant Cells ◽  
Atypical Cell ◽  
Allogenic Stem Cell Transplantation ◽  
Multiple Organs ◽  
Large Atypical Cell

Cytomegalovirus infection related changes frequently remain masked by local symptoms of tumor invasion or therapeutic side effects in cancer patients. The spectrum of cytomegalovirus manifestations, however, can be highly varied and may contribute to the failure of different organs with fatal outcome. The case of a 29-year-old female patient is presented who obtained polychemotherapy and allogenic stem cell transplantation following the diagnosis of classical Hodgkin’s disease. Despite intensified treatment, only partial response could be achieved and the outcome of the disease was death. Postmortem examination revealed regressive lymph node infiltration as well as nodular liver and spleen manifestations of classical Hodgkin’s disease. In addition, parenchymal tissues (lung, kidneys, small intestine, liver, pancreas and ovaries) showed the classical morphology of widespread cytomegalovirus infection. Bilateral enlargement of the ovaries was caused by a partially necrotic giant cell proliferation in the subepithelial cortex. CD30-negativity and cytomegalovirus antigen positivity of the large atypical cell infiltrate supported the diagnosis of cytomegalia oophoritis with morphological overlap between cytomegalovirus-infected giant cells and residual Hodgkin-Reed-Sternberg cells. Further to the cytopathic effect in multiple organs, significant hemophagocytosis was also observed in the spleen, liver and bone marrow. In summary, active cytomegalovirus infection may be a major cause of multi-organ failure in the immunosuppressed oncohematological patient. Careful postmortem analysis demonstrated both the activity of the viral infection and the efficacy of the anti-viral treatment, when applied. Orv. Hetil., 2012, 153, 751–755.

Sign in / Sign up

Export Citation Format

Share Document