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The 2d Distribution Of Iron-Rich Ejecta In The Remnant Of Sn 1885 In M31, Robert A. Fesen, Peter A. Höflich, Andrew J. S. Hamilton May 2015

The 2d Distribution Of Iron-Rich Ejecta In The Remnant Of Sn 1885 In M31, Robert A. Fesen, Peter A. Höflich, Andrew J. S. Hamilton

Dartmouth Scholarship

We present Hubble Space Telescope (HST) ultraviolet Fe i and Fe ii images of the remnant of Supernova 1885 (S And) which is observed in absorption against the bulge of the Andromeda galaxy, M31. We compare these Fe i and Fe ii absorption line images to previous HST absorption images of S And, of which the highest quality and theoretically cleanest is Ca ii H and K. Because the remnant is still in free expansion, these images provide a 2D look at the distribution of iron synthesized in this probable Type Ia explosion, thus providing insights and constraints …


Magnesium Excretion In C. Elegans Requires The Activity Of The Gtl-2 Trpm Channel, Takayuki Teramoto, Laura A. Sternick, Eriko Kage-Nakadai, Shirine Sajjadi, Jakub Siembida, Shohei Mitani, Kouichi Iwasaki, Eric J. Lambie Mar 2010

Magnesium Excretion In C. Elegans Requires The Activity Of The Gtl-2 Trpm Channel, Takayuki Teramoto, Laura A. Sternick, Eriko Kage-Nakadai, Shirine Sajjadi, Jakub Siembida, Shohei Mitani, Kouichi Iwasaki, Eric J. Lambie

Dartmouth Scholarship

Systemic magnesium homeostasis in mammals is primarily governed by the activities of the TRPM6 and TRPM7 cation channels, which mediate both uptake by the intestinal epithelial cells and reabsorption by the distal convoluted tubule cells in the kidney. In the nematode, C. elegans, intestinal magnesium uptake is dependent on the activities of the TRPM channel proteins, GON-2 and GTL-1. In this paper we provide evidence that another member of the TRPM protein family, GTL-2, acts within the C. elegans excretory cell to mediate the excretion of excess magnesium. Thus, the activity of GTL-2 balances the activities of the paralogous …


Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth Jun 1992

Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth

Dartmouth Scholarship

The renal collecting duct is a heterogenous epithelium consisting of intercalated cells (ICC) and principal cells (PC). The origin of this cellular heterogeneity is not clear. To test the hypothesis that the two cell types might originate from one another, pure populations of ICC (beta subtype) and PC were isolated by fluorescence-activated cell sorting and grown on permeable supports. After the monolayers reached confluence, the expression of ICC- and PC-specific functions and antigens was monitored. Cultures of sorted beta-ICC, in addition to expressing ICC-specific functions (such as an electrogenic H+ secretion) and antigens, progressively acquired PC functions (amiloride-sensitive Na+ transport …


K+ Efflux In Nih Mouse 3t3 Cells And Transformed Derivatives: Dependence On Extracellular Ca2+ And Phorbol Esters., Martin Lubin Jul 1988

K+ Efflux In Nih Mouse 3t3 Cells And Transformed Derivatives: Dependence On Extracellular Ca2+ And Phorbol Esters., Martin Lubin

Dartmouth Scholarship

In culture medium deficient in Ca2+, NIH mouse 3T3 cells lose K+, gain Na+, and stop growing. A marked increase in the rate of K+ efflux accounts for this loss; Na+, K+-ATPase pump activity increases but does not fully compensate for enhanced K+ efflux. Phorbol esters and cycloheximide inhibit K+ loss in Ca2+-deficient medium. Phorbol esters inhibit K+ efflux from human fibroblasts as well, even at physiological levels of Ca2+. Two cell lines derived from NIH-3T3, one transformed by a simian virus 40 deletion mutant, the other by the polyoma virus oncogene encoding the middle-sized tumor antigen, retain K+ and …


Regulation By Adrenal Corticosteroids Of Sodium And Potassium Transport In Loop Of Henle And Distal Tubule Of Rat Kidney., Bruce A. Stanton Dec 1986

Regulation By Adrenal Corticosteroids Of Sodium And Potassium Transport In Loop Of Henle And Distal Tubule Of Rat Kidney., Bruce A. Stanton

Dartmouth Scholarship

Studies were conducted to examine the effects of adrenalectomy (ADX) and selective, physiological adrenal corticosteroid replacement on sodium and potassium transport by the superficial loop of Henle and distal tubule of rat kidney in vivo. In the loop of Henle, ADX inhibited sodium reabsorption by 33%. Whereas dexamethasone had no effect on reabsorption, aldosterone increased sodium transport to control levels. Thus, physiological levels of mineralocorticoids, but not glucocorticoids, control a fraction of sodium reabsorption in the loop of Henle. ADX also inhibited potassium reabsorption in the loop of Henle. Both dexamethasone and aldosterone reversed the inhibition, although only aldosterone increased …