Potexviruses frequently infect plants from the family Cactaceae. We report the complete genome sequence of a new Schlumbergera virus X (SchVX) isolate. The genome has 6,615 nucleotides and shares 94% nucleotide identity with SchVX-K11 from Schlumbergera. This is the first sequence of an isolate of SchVX from the genus Opuntia.

In this note, we define the notion of a cactus set, and show that its geometric realization has a natural structure as an algebra over Voronov’s cactus operad, which is equivalent to the framed 2-dimensional little disks operad D2. Using this, we show that for a Poincaré algebra A, its Hochschild cohomology is an algebra over the (chain complexes of) D2.

While the statics of many simple physical systems reproduce the striking number-theoretical patterns found in the phyllotaxis of living beings, their dynamics reveal unusual excitations: multiple classical rotons and a large family of interconverting topological solitons. As we introduce those, we also demonstrate experimentally for the first time Levitov's celebrated model for phyllotaxis. App...

The X-ray diffractometric and infrared spectroscopic investigation of crystalline material isolated from the Cactaceae species Opuntia ellisiana shows the presence of a very complex mineral composition, including whewellite (monohydrated calcium oxalate), opal (SiO2), calcite (CaCO3) and glushinskite (dihydrated magnesium oxalate). This is the first report of the presence of magnesium oxalate i...

A bisection of a set U is a partition of U into two nonempty parts. Two bisections are parallel if they collectively partition U into three parts. A natural model for a family of pairwise parallel bisections is a tree. Given a bisection family F and a family T of pairwise parallel bisections, we suggest decomposition/composition tools for modeling F based on T . We introduce plant models result...

A new species of Dactylopius Costa (Dactylopius gracilipilus Van Dam & May) is described and illustrated. It is morphologically similar to Dactylopius tomentosus (Lamarck), but has more gracile truncate setae, abundant simple pores dorsally, and appears to be host-restricted to Corynopuntia Knuth (Cactaceae: Opuntioidea).

Frequently, vital rates are driven by directional, long-term environmental changes. Many of these are of great importance, such as land degradation, climate change, and succession. Traditional demographic methods assume a constant or stationary environment, and thus are inappropriate to analyze populations subject to these changes. They also require repeat surveys of the individuals as change u...