In the title chiral aldimine, C(19)H(17)N, the azomethine group is not fully conjugated with the phenyl substituent: the dihedral angle between phenyl and C(*)-N=C mean planes is ϕ(3) = 23.0 (2)°. Compared with the earlier DFT-B3LYP/6-31 G(d) computations from the literature, the C=N-C(*)-C(naph-thyl) torsion angle, found at ϕ(2) = -118.0 (2)° in the X-ray structure, does not match the angle ca...

For positive integers s and t, let f (sÒ t) denote the smallest positive integer N such that every 2-colouring of [1ÒN] = f1Ò 2Ò    ÒNg has a monochromatic homothetic copy of f1Ò 1 + sÒ 1 + s + tg. We show that f (sÒ t) = 4(s + t) + 1 whenever sÛg and tÛg are not congruent to 0 (modulo 4), where g = gcd(sÒ t). This can be viewed as a generalization of part of van der Waerden’s theorem on ari...

Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis of dairy domestic ruminants. This agent produces a variety of extracellular toxins and virulence factors including Toxic Shock Syndrome Toxin-1 (TSST-1) which is the major cause of Toxic Shock Syndrome (TSS). In this study 58 S. aureus isolates obtained from 9 dairy herds in East and West Azerbaijan provinc...

Cover photo: A vigilant yellow-bellied marmot (Marmota flaviventris) at the Rocky Mountain Biological Laboratory, Colorado, USA. Blumstein et al. (pp. 879–887) report that the time allocated to anti-predator vigilance in marmots is heritable and is weakly correlated with locomotor performance. Interestingly, faster marmots allocate more time to vigilance while slower marmots allocate less time....

Abstract For all positive integers s and t, Brown et. al [1] defined f(s, t) to be the smallest positive integer N such that every 2-coloring of [1, N ] has a monochromatic homothetic copy of {1, 1+ s, 1+ s+ t}. They proved that f(s, t) ≤ 4(s + t) + 1 for all s, t and that the equality holds in the case where both s/g 6≡ 0 (mod 4) and t/g 6≡ 0 (mod 4) with g = gcd(s, t) and in many other cases....