We construct examples of families of curves of genus 2 or 3 over Q whose Jacobians split completely and have various large rational torsion subgroups. For example, the rational points on a certain elliptic surface over P of positive rank parameterize a family of genus-2 curves over Q whose Jacobians each have 128 rational torsion points. Also, we find the genus-3 curve 15625(X + Y 4 + Z)− 96914...

We describe a part of the lattice of subvarieties of left distributive left idempotent groupoids (i.e. those satisfying the identities x(yz) ≈ (xy)(xz) and (xx)y ≈ xy) modulo the lattice of subvarieties of left distributive idempotent groupoids. A free groupoid in a subvariety of LDLI groupoids satisfying an identity x ≈ x decomposes as the direct product of its largest idempotent factor and a ...

A new type II restriction endonuclease, CviRI, was isolated from virus XZ-6E infected chlorella cells. CviRI is the first restriction endonuclease to recognize the sequence 5'-TGCA-3' and cleaves DNA between the G and C residues to produce blunt-end termini. Methylation of the adenine or cytosine in 5'-TGCA-3' sequences prevents CviRI cleavage. Due to its sequence specificity, CviRI may be espe...

We studied the band structure of $\mathrm{Nd}\phantom{\rule{0.16em}{0ex}}\mathrm{Fe}\phantom{\rule{0.16em}{0ex}}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{P}}_{x}{\mathrm{O}}_{0.9}{\mathrm{F}}_{0.1}$ ($x=0$, 0.2, 0.4, and 0.6) using angle-resolved photoemission spectroscopy (ARPES) measurements. Two hole bands, ${\ensuremath{\alpha}}_{1}$ $({d}_{xz})$ ${\ensuremath{\alpha}}_{3}$ $({d}_{{z}^{2}})$...

The synthesis, spectroscopy and magnetic characterization of five new dinuclear copper(II) complexes are described. All five compounds have the general formula [Cu2(L)4(O-R)2](Cl)2 or [Cu2(L)2(Cl)2](Cl)2, in which R = CH3 or H, L=2, 3 or 4-pyridinemethanol as L2, L3 or L4, respectively. The title compounds consist of dinuclear units with bridging methoxo groups in [Cu2(L4)4(O-CH3)2](Cl)2, hydro...

Stability of the ;-; stacking interactions in the substituted-coronene||cyclooctatetraene complexes wasstudied using the computational quantum chemistry methods (where || denotes ;–; stackinginteraction, and substituted-coronene is coronene which substituted with four similar X groups; X =OH, SH, H, F, CN, and NO). There are meaningful correlations between changes of geometricalparameters and t...

A bull is a graph with five vertices r, y, x, z, s and five edges ry, yx, yz, xz, zs. A graph G is bull-reducible if no vertex of G lies in two bulls. We prove that every bull-reducible Berge graph G that contains no antihole is weakly chordal, or has a homogeneous set, or is transitively orientable. This yields a fast polynomial time algorithm to color exactly the vertices of such a graph.