scholarly journals Trapped Gravitational Waves in Jackiw–Teitelboim Gravity

Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Jeong-Myeong Bae ◽  
Ido Ben-Dayan ◽  
Marcelo Schiffer ◽  
Gibum Yun ◽  
Heeseung Zoe
Keyword(s):  
Active Region ◽  
Thin Layer ◽  
Gravitational Waves ◽  
Two Dimensional ◽  
Effective Energy ◽  
Region Approach ◽  
Metric Fluctuations

We discuss the possibility that gravitational fluctuations (“gravitational-waves”) are trapped in space by gravitational interactions in two dimensional Jackiw–Teitelboim gravity. In the standard geon (gravitational electromagnetic entity) approach, the effective energy is entirely deposited in a thin layer, the active region, that achieves spatial self-confinement and raises doubts about the geon’s stability. In this paper we relinquish the “active region” approach and obtain self-confinement of “gravitational waves” that are trapped by the vacuum geometry and can be stable against the backreaction due to metric fluctuations.

scholarly journals Studies on the autophosphorylation of the insulin receptor from human placenta. Analysis of the sites phosphorylated by two-dimensional peptide mapping

1988 ◽  
Vol 252 (2) ◽  
pp. 607-615 ◽  
Author(s):  
J M Tavaré ◽  
R M Denton
Keyword(s):  
Thin Layer ◽  
Insulin Receptor ◽  
Peptide Mapping ◽  
Beta Subunit ◽  
Two Dimensional ◽  
Intact Cells ◽  
Tyrosine Residues ◽  
Domain 3 ◽  
Receptor Beta

1. A partially purified preparation of human placental insulin receptors was incubated with [gamma-32P]ATP in the presence or absence of insulin. The 32P-labelled insulin-receptor beta-subunits were then isolated, cleaved with trypsin followed by protease V8 and the [32P]phosphopeptides generated were analysed by thin layer electrophoresis and chromatography. This approach revealed that insulin stimulates autophosphorylation of the insulin-receptor beta-subunit in vitro on at least seven tyrosine residues distributed among three distinct domains. 2. One domain (domain 2), containing tyrosine residues 1146, 1150 and 1151 was the most rapidly phosphorylated and could be recovered as mono-, di- and triphosphorylated peptides cleaved by trypsin at Arg-1143 and either Lys-1153 or Lys-1156. Multiple phosphorylation of this domain appears to partially inhibit the cleavage at Lys-1153 by trypsin. 3. In a second domain (domain 3) containing two phosphorylated tyrosine residues at positions 1316 and 1322 the tyrosines were phosphorylated more slowly than those in domain 2. This domain is close to the C-terminus of the beta-subunit polypeptide chain. 4. At least two further tyrosine residues appeared to be phosphorylated after those in domains 2 and 3. These residues probably residue within a domain lying in close proximity to the inner face of the plasma membrane containing tyrosines 953, 960 and 972, but conclusive evidence is still required. 5. The two-dimensional thin-layer analysis employed in this study to investigate insulin-receptor phosphorylation has several advantages over previous methods based on reverse-phase chromatography. It allows greater resolution of 32P-labelled tryptic peptides and, when coupled to radioautography, is considerably more sensitive. The approach can be readily adapted to study phosphorylation of the insulin receptor within intact cells.

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