Solving Pell’s equation is of relevance in finding fundamental units in real quadratic fields and for this reason polynomial solutions are of interest in that they can supply the fundamental units in infinite families of such fields. In this paper an algorithm is described which allows one to construct, for each positive integer n, a finite collection, {Fi}, of multi-variable polynomials (with ...

Red blood cells deliver O(2) from the lungs to every cell in the human body. Reduced tissue oxygenation triggers increased production of erythropoietin by hypoxia-inducible factor 1 (HIF-1), which is a transcriptional activator composed of an O(2)-regulated alpha subunit and a constitutively expressed beta subunit. Hydroxylation of HIF-1alpha or HIF-2alpha by the asparaginyl hydroxylase FIH-1 b...

Current concepts of cellular oxygen-sensing include an isoform of the neutrophil NADPH oxidase, different electron carrier units of the mitochondrial electron transport chain (ETC), heme oxygenase-2 (HO-2), and a subfamily of 2-oxoglutarate dependent dioxygenases termed HIF (hypoxia inducible factor) prolyl hydroxylases (PHDs) and HIF asparagyl hydroxylase FIH-1 (factor-inhibiting HIF). Differe...

Methylation of histone tails is a key determinant in forming active and silent states of chromatin. Histone methylation was regarded as irreversible until the recent identification of a lysine-specific histone demethylase (LSD1), which acts specifically on mono- and dimethylated histone H3 lysine 4. Here, we propose that the fission yeast protein Epe1 is a putative histone demethylase that coul...