Infinitesimal cohomology and the Chern character to negative cyclic homology

There is a Chern character from K-theory to negative cyclic homology. We show that it preserves the decomposition coming from Adams operations, at least in characteristic 0. This is done by using infinitesimal cohomology to reduce to the case of a nilpotent ideal (which had been established by Cathelineau some time ago).Comment: Included reference for identification of relative Chern and rational homotopy theory characters; some minor editing for clarit

The Yoneda algebra of a graded Ore extension

Let A be a connected-graded algebra with trivial module k, and let B be a graded Ore extension of A. We relate the structure of the Yoneda algebra E(A) := Ext_A(k,k) to E(B). Cassidy and Shelton have shown that when A satisfies their K_2 property, B will also be K_2. We prove the converse of this result.Comment: 9 page

Development of an Organic Table Grape Production and Market in Switzerland

In Switzerland there is an increasing consumer demand for residue-free, organic table grapes. The organic cultivation of table grapes, however, is very delicate in humid climates and experience to advice organic growers is still lacking. The goal of our project that has started in 2004 is to develop and establish a cultivation system for organic table grapes under Swiss climatic and economic conditions with a high yield security and fulfilling the high quality demands of the market. Preliminary results: Interesting cultivars to produce are e.g. Fanny, Lilla, Palatina. However they are disease susceptible and must be produced under a rain roof. Better suited cultivars still need to be found. Consumer acceptance for organic table grapes produced in Switzerland is very positive. However changes towards new cultivars and lower production costs are necessary. Spray programs to achieve sufficient disease protection and no spray blotch seem to be realizable, mainly for production under rain roof

The K-theory of toric varieties in positive characteristic

We show that if X is a toric scheme over a regular ring containing a field then the direct limit of the K-groups of X taken over any infinite sequence of nontrivial dilations is homotopy invariant. This theorem was known in characteristic 0. The affine case of our result was conjectured by Gubeladze.Comment: Companion paper to arXiv:1106.138

Toric varieties, monoid schemes and cdhcdh descent

We give conditions for the Mayer-Vietoris property to hold for the algebraic K-theory of blow-up squares of toric varieties in any characteristic, using the theory of monoid schemes. These conditions are used to relate algebraic K-theory to topological cyclic homology in characteristic p. To achieve our goals, we develop for monoid schemes many notions from classical algebraic geometry, such as separated and proper maps.Comment: v2 changes: field of positive characteristic replaced by regular ring containing such a field at appropriate places. Minor changes in expositio