A selection of points drawn from a convex polygon, no two with the same vertical or horizontal coordinate, yields a permutation in a canonical fashion. We characterise and enumerate those permutations which arise in this manner and exhibit some interesting structural properties of the permutation class they form. We conclude with a permutation analogue of the celebrated Happy Ending Problem. 1 ...

We present continuum observations of a small sample of high-redshift, radio-loud AGN (radio galaxies and quasars) aimed at the detection of thermal emission from dust. Seven AGN were observed with IRAM and SEST at 1.25mm; two of them, the radio galaxies 1243+036 (z ∼ 3.6) and MG1019+0535 (z ∼ 2.8) were also observed at 0.8mm with the JCMT submillimetre telescope. Additional VLA observations wer...

Rapid identification and large-scale mapping of salt-affected lands will help improve salinity management in watersheds and ecosystems. This study was conducted to examine spectral reflectance of soils treated with saline solutions containing NaCl, NaHCO3, Na2SO4, and CaSO4.2H2O. Spectral reflectance was measured upon salt crusts formed on two soils (Torrifluvents) subirrigated with saline solu...

Primers for PCR were selected from a sequenced fragment of clone pL590, which contains a repetitive element present in the genome of Leptospira interrogans serovar hardjo type hardjoprajitno (M. L. Pacciarini, M. L. Savio, S. Tagliabue, and C. Rossi, J. Clin. Microbiol. 30:1243-1249, 1992). A specific DNA fragment was amplified from the genomic DNAs of serovar hardjo type hardjoprajitno and nin...

Sn(π1, π2, . . . , πr) denotes the set of permutations of length n that have no subsequence with the same order relations as any of the πi. In this paper we show that |Sn(1342, 2143)| = |Sn(3142, 2341)| and |Sn(1342, 3124)| = |Sn(1243, 2134)|. These two facts complete the classification of Wilf-equivalence classes for pairs of permutations of length four. In both instances we exhibit bijections...