scholarly journals On the Origin of Metallicity in Lyman-Alpha Forest Systems

2002 ◽  
Vol 187 ◽  
pp. 123-127
Author(s):  
M. Chiba ◽  
B. B. Nath
Keyword(s):  
High Resolution ◽  
Column Density ◽  
Large Fraction ◽  
The Other ◽  
Absorption Lines ◽  
Lyman Alpha ◽  
Other Hand ◽  
Lyman Alpha Forest

Several recent observations indicate that even the low H I column density Lyα absorption lines may not be primordial, as they were previously thought to be. High-resolution observations using the Keck telescope (Cowie et al. 1995; Tytler et al 1995.; Songaila & Cowie 1996) have revealed that a large fraction of Lyα absorption lines with H I column density as low as NHI ~ 1014 cm−2 at redshift z ~ 3 are associated with metal lines (C IV). This fraction, hereafter denoted as fm, is estimated as 0.5-0.75. On the other hand, there is an indication that at low z a large fraction of Lyα absorption lines are directly associated with halos of visible galaxies. This fraction is hereafter denoted as fg. Lanzetta et al. (1995, hereafter LBTW) claimed fg ~ 0.6 at z ≲ 1 (see also Bowen, Pettini & Boyle 1997).

“Virtual” Atmospheric and Oceanic Circulation in the Earth Simulator

2007 ◽  
Vol 88 (6) ◽  
pp. 861-866 ◽  
Author(s):  
Wataru Ohfuchi ◽  
Hideharu Sasaki ◽  
Yukio Masumoto ◽  
Hisashi Nakamura
Keyword(s):  
High Resolution ◽  
The Other ◽  
Educational Community ◽  
Oceanic Circulation ◽  
Close Collaboration ◽  
Simulation Research ◽  
The Earth ◽  
Other Hand ◽  
Early Results

High-resolution simulations of the atmospheric and oceanic general circulations on the Earth Simulator are briefly introduced to a wider research and educational community. Some early results have been published and are reviewed in this article. The high-resolution simulations may have more information in certain aspects than observations while the simulations need to be validated. On the other hand, high-resolution observations in which uncertainties are unavoidable are now available. Possible close collaboration between observational and simulation research is proposed.

scholarly journals Spatial Correlations of Selected DIBs to the CH and CH+ Molecules

2013 ◽  
Vol 9 (S297) ◽  
pp. 128-131
Author(s):  
T. Weselak ◽  
J. Krełowski
Keyword(s):  
Equivalent Width ◽  
Column Density ◽  
Radial Velocities ◽  
The Other ◽  
Spatial Correlations ◽  
Ob Stars ◽  
Other Hand

AbstractThe analysis of radial velocities in the spectra of HD 151932 and HD 152233, performed for the optical lines of interstellar CH and CH+ molecules on one hand, and for the diffuse bands 4964 and 6196 Å on the other hand, suggests that the carrier of the former DIB is spatially related to CH, while the carrier of the latter - to CH+. A further analysis, based on the sample of 106 reddened OB stars, partly confirms this suggestion, showing that the CH column density correlates indeed much better with the equivalent width of the 4964 DIB than with that of the 6196 DIB.

scholarly journals The big unknown: The asymptomatic spread of COVID-19

BIOMATH ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 2005103 ◽  
Author(s):  
Roumen Anguelov ◽  
Jacek Banasiak ◽  
Chelsea Bright ◽  
Jean Lubuma ◽  
Rachid Ouifki
Keyword(s):  
Significant Role ◽  
Large Fraction ◽  
Herd Immunity ◽  
The Other ◽  
Other Hand ◽  
The One

The paper draws attention to the asymptomatic and mildly symptomatic cases of COVID-19, which, according to some reports, may constitute a large fraction of the infected individuals. These cases are often unreported and are not captured in the total number of confirmed cases communicated daily. On the one hand, this group may play a significant role in the spread of the infection, as asymptomatic cases are seldom detected  and quarantined. On the other hand, it may play a significant role in disease extinction by contributing to the development of sufficient herd immunity.

Mapping of adherens junction components using microscopic resonance energy transfer imaging

1995 ◽  
Vol 108 (3) ◽  
pp. 1051-1062 ◽  
Author(s):  
Z. Kam ◽  
T. Volberg ◽  
B. Geiger
Keyword(s):  
Energy Transfer ◽  
High Resolution ◽  
Resonance Energy Transfer ◽  
Focal Adhesions ◽  
Resonance Energy ◽  
Ccd Camera ◽  
The Other ◽  
Molecular Organization ◽  
Other Hand ◽  
Immunofluorescence Labeling

Quantitative microscopic imaging of resonance energy transfer (RET) was applied for immunological high resolution proximity mapping of several cytoskeletal components of cell adhesions. To conduct this analysis, a microscopic system was developed, consisting of a highly stable field illuminator, computer-controlled filter wheels for rapid multiple-color imaging and a sensitive, high resolution CCD camera, enabling quantitative data recording and processing. Using this system, we have investigated the spatial inter-relationships and organization of four adhesion-associated proteins, namely vinculin, talin, alpha-actinin and actin. Cultured chick lens cells were double labeled for each of the junctional molecules, using fluorescein- and rhodamine-conjugated antibodies or phalloidin. RET images were acquired with fluorescein excitation and rhodamine emission filter setting, corrected for fluorescein and rhodamine fluorescence, and normalized to the fluorescein image. The results pointed to high local densities of vinculin, talin and F-actin in focal adhesions, manifested by mean RET values of 15%, 12% and 10%, respectively. On the other hand, relatively low values (less than 1%) were observed following double immunofluorescence labeling of the same cells for alpha-actinin. Double indirect labeling for pairs of these four proteins (using fluorophore-conjugated antibodies or phalloidin) resulted in RET values of 5% or lower, except for the pair alpha-actinin and actin, which yielded significantly higher values (13-15%). These results suggest that despite their overlapping staining patterns, at the level of resolution of the light microscope, the plaque proteins vinculin and talin are not homogeneously interspersed at the molecular level but form segregated clusters. alpha-Actinin, on the other hand, does not appear to form such clusters but, rather, closely interacts with actin. We discuss here the conceptual and applicative aspects of RET measurements and the implications of the results on the subcellular molecular organization of adherens-type junctions.

The Lyman-Alpha Forest of PKS 2126-158 at High Resolution

1993 ◽  
Vol 416 ◽  
pp. 137 ◽  
Author(s):  
Emanuele Giallongo ◽  
Stefano Cristiani ◽  
Adriano Fontana ◽  
Dario Trevese
Keyword(s):  
High Resolution ◽  
Lyman Alpha ◽  
Lyman Alpha Forest

TEMPERATURE-DEPENDENT HIGH-RESOLUTION PHOTOEMISSION SPECTROSCOPY OF YbXCu4 (X=In, Cd, Mg)

2002 ◽  
Vol 09 (02) ◽  
pp. 1079-1083 ◽  
Author(s):  
H. SATO ◽  
Y. NISHIKAWA ◽  
F. NAGASAKI ◽  
H. FUJINO ◽  
Y. TAKEDA ◽  
...  
Keyword(s):  
High Resolution ◽  
Valence Band ◽  
Energy Resolution ◽  
High Energy ◽  
The Other ◽  
High Energy Resolution ◽  
Photoemission Spectroscopy ◽  
Temperature Dependent ◽  
Other Hand ◽  
Increasing Temperature

Valence-band and Yb 4d photoemission spectra of YbXCu 4 (X=In, Cd, Mg) have been measured with high energy resolution from 10 to 300 K. In the valence-band photoemission spectra of YbInCu 4 and YbCdCu 4, the structure due to the Yb 2+ 4f 7/2 states is clearly observed near the Fermi level (E F ) at 10 K. The intensity of the Yb 2+ 4f 7/2 structure decreases with increasing temperature and the structure almost disappears at 300 K. The amount of the enhancement from 50 to 107 K is much stronger for YbInCu 4 than for YbCdCu 4. On the other hand, the Yb 2+ 4f 7/2 structure of YbMgCu 4 is observed as a broad peak near E F and the spectra show little temperature dependence. In the Yb 4d photoemission spectra of YbInCu 4 and YbCdCu 4, the structures due to the Yb 2+ and Yb 3+ states are recognized. The intensity ratio Yb 2+/ Yb 3+ increases with decreasing temperature. In the Yb 4d spectra of YbMgCu 4, on the other hand, almost only structures due to Yb 2+ states are observed.

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