606 research outputs found
Migrant Land Birds and Water Birds in the Mariana Islands
Approximately 56 species of land and freshwater birds have been
recorded as migrants or vagrants in the Mariana Islands, but few occur in substantial
numbers. Common migrants include the Tufted Duck (Aythya fuligula), Northern
Pintail (Anas acuta), and Cattle Egret (Bubulcus ibis). Several other heron and duck
species appear most years in small numbers. The Barn Swallow (Hirundo rustica)
is the only regular migrant land bird. A similar assemblage of herons and waterfowl
has been reported from the Ogasawara and Iwo Islands to the north. Many more
species of migrant land birds occur in the Ogasawara and Iwo groups and in Palau
to the southwest, which are closer to large land masses
Ariel - Volume 6 Number 2
Editors
Mark Dembert
J.D. Kanofsky
Frank Chervenak
John Lammie
Curt Cummings
Entertainment
Robert Breckenridge
Joe Conti
Gary Kaskey
Photographer
Larry Glazerman
Overseas Editor
Mike Sinason
Humorist
Jim McCann
Staff
Ken Jaffe
Bob Skarloff
Halley Faust
Jim Burk
Ariel - Volume 5 Number 4
Editors
Mark Dembert
J.D. Kanofskv
Entertainment Editors
Robert Breckenridge
Joe Conti
Overseas Editor
Mike Sinason
Photographer
Scott Kastner
Epistemologist
Gary Kaskey
Staff
Ken Jaffe
Bob Sklaroff
Janet Weish
David Jacoby
Phil Nimoityn
Circulation Editor
Jay Amsterdam
Humorist
Jim Mccan
Ariel - Volume 6 Number 3
Editors
Mark Dembert
J.D. Kanofsky
Frank Chervenak
John Lammie
Curt Cummings
Staff
Ken Jaffe
Bob Sklaroff
Halley Faust
Jim Burke
Nancy Redfern
Hans Weltin
Photographer
Larry Glazerman
Overseas Editor
Mike Sinason
Humorist
Jim McCan
Ariel - Volume 5 Number 5
Editors
Mark Dembert
J. D. Kanofsky
Entertainment
Robert Breckenridge
Joe Conti
Gary Kaskey
Photographer
Scot Kastner
Overseas Editor
Mike Sinason
Circulation
Jay Amsterdam
Humorist
Jim McCann
Staff
Ken Jaffe
Bob Sklaroff
Janet Welsh
Dave Jacoby
Phil Nimoityn
Frank Chervane
Ariel - Volume 4 Number 5
Editors
David A. Jacoby
Eugenia Miller
Tom Williams
Associate Editors
Paul Bialas
Terry Burt
Michael Leo
Gail Tenikat
Editor Emeritus and Business Manager
Richard J. Bonnano
Movie Editor
Robert Breckenridge
Staff
Richard. Blutstein
Mary F. Buechler
Alice M. Johnson
J.D. Kanofskv
Rocky Webe
Ariel - Volume 4 Number 3
Editors
David A. Jacoby
Eugenia Miller
Tom Williams
Associate Editors
Paul Bialas
Terry Burt
Michael Leo
Gail Tenikat
Editor Emeritus and Business Manager
Richard J. Bonnano
Movie Editor
Robert Breckenridge
Staff
Richard Blutstein
Mary F. Buechler
Steve Glinks
Len Grasman
Alice M. Johnson
J.D. Kanofsky
Tom Lehman
Dave Mayer
Bernie Odd
Mossbauer and optical spectroscopic study of temperature and redox effects on iron local environments in a Fe-doped (0.5 mol% Fe2O3)18Na2Oâ72SiO2 glass
Local environments of ferric and ferrous irons were systematically studied with Mössbauer (at liquid helium temperature)and ultravioletâvisibleânear infrared spectroscopic methods for various 18Na2Oâ72SiO2 glasses doped with 0.5 mol% Fe2O3. These were prepared at temperatures of 1300â1600 °C in ambient air or at 1500 °C under reducing conditions with oxygen partial pressures from 12.3 to 0.27 x 10-7 atmospheres. The Mössbauer spectroscopic method identified three types of local environments, which were represented by the Fe3+ sextet, the Fe3+ doublet, and the Fe2+ doublet. The Fe3+ sextet ions were assigned to âisolatedâ octahedral ions. Under reducing conditions, the octahedral Fe3+ ions were readily converted into octahedral ferrous ions. The Fe3+ doublet exists both in octahedral and tetrahedral environment, mainly as tetrahedral sites in the reduced samples. The tetrahedral ions were found stable against reduction to ferrous ions. The Fe2+ doublet sites existed in octahedral coordination. Combining results from both spectroscopic studies, the 1120- and 2020-nm optical bands were assigned to octahedral ferrous ions with a different degree of distortion rather than different coordinations. Further, we assigned the 375-nm band to the transition of octahedral ferric ions that are sensitive to the change of oxygen partial pressure in glass melting and 415-, 435-, and 485-nm bands to the transitions of the tetrahedral ferric ions that are insensitive to oxidation states of the melt. The effect of ferric and ferrous ions with different coordination environments on the glass immiscibility was elucidated
A Nonlinear Force-Free Magnetic Field Approximation Suitable for Fast Forward-Fitting to Coronal Loops. I. Theory
We derive an analytical approximation of nonlinear force-free magnetic field
solutions (NLFFF) that can efficiently be used for fast forward-fitting to
solar magnetic data, constrained either by observed line-of-sight magnetograms
and stereoscopically triangulated coronal loops, or by 3D vector-magnetograph
data. The derived NLFFF solutions provide the magnetic field components
, , , the force-free parameter
, the electric current density , and are
accurate to second-order (of the nonlinear force-free -parameter). The
explicit expressions of a force-free field can easily be applied to modeling or
forward-fitting of many coronal phenomena.Comment: Solar Physics (in press), 26 pages, 11 figure
Nonthermal atmospheric pressure plasma enhances mouse limb bud survival, growth, and elongation.
The enhanced differentiation of mesenchymal cells into chondrocytes or osteoblasts is of paramount importance in tissue engineering and regenerative therapies. A newly emerging body of evidence demonstrates that appendage regeneration is dependent on reactive oxygen species (ROS) production and signaling. Thus, we hypothesized that mesenchymal cell stimulation by nonthermal (NT)-plasma, which produces and induces ROS, would (1) promote skeletal cell differentiation and (2) limb autopod development. Stimulation with a single treatment of NT-plasma enhanced survival, growth, and elongation of mouse limb autopods in an in vitro organ culture system. Noticeable changes included enhanced development of digit length and definition of digit separation. These changes were coordinated with enhanced Wnt signaling in the distal apical epidermal ridge (AER) and presumptive joint regions. Autopod development continued to advance for approximately 144âh in culture, seemingly overcoming the negative culture environment usually observed in this in vitro system. Real-time quantitative polymerase chain reaction analysis confirmed the up-regulation of chondrogenic transcripts. Mechanistically, NT-plasma increased the number of ROS positive cells in the dorsal epithelium, mesenchyme, and the distal tip of each phalange behind the AER, determined using dihydrorhodamine. The importance of ROS production/signaling during development was further demonstrated by the stunting of digital outgrowth when anti-oxidants were applied. Results of this study show NT-plasma initiated and amplified ROS intracellular signaling to enhance development of the autopod. Parallels between development and regeneration suggest that the potential use of NT-plasma could extend to both tissue engineering and clinical applications to enhance fracture healing, trauma repair, and bone fusion
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