Curious Properties of Iterative Sequences

In this study, several interesting iterative sequences were investigated. First, we define the iterative sequences. We fix function f(n). An iterative sequence starts with a natural number n, and calculates the sequence f(n),f(f(n)), ...f(f(f(f(n)))),... We then search for interesting features in this sequence. We study Kaprekar's routine, the digit factorial process, and the digit power process. The authors presented new variants of Kaprekar's routine.Comment: This is already submitted to a journa

Pleiotrophin-induced endothelial cell migration is regulated by xanthine oxidase-mediated generation of reactive oxygen species

Pleiotrophin (PTN) is a heparin-binding growth factor that induces cell migration through binding to its receptor protein tyrosine phosphatase beta/zeta (RPTPβ/ζ) and integrin alpha v beta 3 (ανβ3). In the present work, we studied the effect of PTN on the generation of reactive oxygen species (ROS) in human endothelial cells and the involvement of ROS in PTN-induced cell migration. Exogenous PTN significantly increased ROS levels in a concentration and time-dependent manner in both human endothelial and prostate cancer cells, while knockdown of endogenous PTN expression in prostate cancer cells significantly down-regulated ROS production. Suppression of RPTPβ/ζ through genetic and pharmacological approaches, or inhibition of c-src kinase activity abolished PTN-induced ROS generation. A synthetic peptide that blocks PTN–ανβ3 interaction abolished PTN-induced ROS generation, suggesting that ανβ3 is also involved. The latter was confirmed in CHO cells that do not express β3 or over-express wild-type β3 or mutant β3Y773F/Y785F. PTN increased ROS generation in cells expressing wild-type β3 but not in cells not expressing or expressing mutant β3. Phosphoinositide 3-kinase (PI3K) or Erk1/2 inhibition suppressed PTN-induced ROS production, suggesting that ROS production lays down-stream of PI3K or Erk1/2 activation by PTN. Finally, ROS scavenging and xanthine oxidase inhibition completely abolished both PTN-induced ROS generation and cell migration, while NADPH oxidase inhibition had no effect. Collectively, these data suggest that xanthine oxidase-mediated ROS production is required for PTN-induced cell migration through the cell membrane functional complex of ανβ3 and RPTPβ/ζ and activation of c-src, PI3K and ERK1/2 kinases

Hepatocyte nuclear factor 4Α is implicated in endoplasmic reticulum stress–induced acute phase response by regulating expression of cyclic adenosine monophosphate responsive element binding protein H Potential conflict of interest: Nothing to report.

Loss of the nuclear hormone receptor hepatocyte nuclear factor 4Α (HNF4Α) in hepatocytes results in a complex pleiotropic phenotype that includes a block in hepatocyte differentiation and a severe disruption to liver function. Recent analyses have shown that hepatic gene expression is severely affected by the absence of HNF4Α, with expression of 567 genes reduced by ≥2.5-fold ( P ≤ 0.05) in Hnf4Α −/− fetal livers. Although many of these genes are direct targets, HNF4Α has also been shown to regulate expression of other liver transcription factors, and this raises the possibility that the dependence on HNF4Α for normal expression of some genes may be indirect. We postulated that the identification of transcription factors whose expression is regulated by HNF4Α might reveal roles for HNF4Α in controlling hepatic functions that were not previously appreciated. Here we identify cyclic adenosine monophosphate responsive element binding protein H ( CrebH ) as a transcription factor whose messenger RNA can be identified in both the embryonic mouse liver and adult mouse liver and whose expression is dependent on HNF4Α. Analyses of genomic DNA revealed an HNF4Α binding site upstream of the CrebH coding sequence that was occupied by HNF4Α in fetal livers and facilitated transcriptional activation of a reporter gene in transient transfection analyses. Although CrebH is highly expressed during hepatogenesis, CrebH −/− mice were viable and healthy and displayed no overt defects in liver formation. However, upon treatment with tunicamycin, which induces an endoplasmic reticulum (ER)–stress response, CrebH −/− mice displayed reduced expression of acute phase response proteins. Conclusion: These data implicate HNF4Α in having a role in controlling the acute phase response of the liver induced by ER stress by regulating expression of CrebH. (H EPATOLOGY 2008.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61225/1/22439_ftp.pd

The International Linear Collider: Report to Snowmass 2021

The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community