Fassett's locoweed (Oxytropis campestris var. chartacea, Fabaceae) is an endangered perennial endemic to Wisconsin. Patterns of genetic variation within and among six remaining populations and their relationship to other members of the O. campestris complex were analysed using AFLPs from 140 accessions across northern North America. Within-population measures of genetic diversity were high (mea...

Many bacterial, viral and parasitic pathogens undergo antigenic variation to counter host immune defense mechanisms. In Plasmodium falciparum, the most lethal of human malaria parasites, switching of var gene expression results in alternating expression of the adhesion proteins of the Plasmodium falciparum-erythrocyte membrane protein 1 class on the infected erythrocyte surface. Recombination c...

The Plasmodium falciparum genome being AT-rich, the presence of GC-rich regions suggests functional significance. Evolution imposes selection pressure to retain functionally important coding and regulatory elements. Hence searching for evolutionarily conserved GC-rich, intergenic regions in an AT-rich genome will help in discovering new coding regions and regulatory elements. We have used eleva...

Our research groups have previously published a study estimating the bottleneck size of Cauliflower mosaic virus (CaMV) during host plant colonization [1]. Two methods were used in that study, both based on the temporal evolution of neutral marker frequencies; one uses estimates of FST, and the other tracks changes in marker frequency variance over time. Here we report that (i) the variance-bas...

where y = [yl y~ " ' " y~]' has covariance mat r ix r and is uncorre la ted wi th z = [zl z2 . z~]' which has covar iance mat r ix A, so t h a t z¢ is uncorre la ted wi th zi , 1 < i _~ j < p. T h e variable y~ is called the common-fac tor c o m p o n e n t of x~ and var(y~) -1 -~ is the communa l i ty of x¢ while z~ is the specific fac tor of x~ and var(z~) = ~ is the uniqueness of x¢ . Le t p...

We study the low temperature properties of p-spin glass models with finite connectivity and of some optimization problems. Using a one-step functional replica symmetry breaking ansatz we can solve exactly the saddle-point equations for graphs with uniform connectivity. The resulting ground state energy is in perfect agreement with numerical simulations. For fluctuating connectivity graphs, the ...

Faba bean (Vicia faba) production in Mediterranean and Near East agriculture is severely constrained by broomrape infection. The most widely distributed broomrape species affecting faba bean is Orobanche crenata, although O. foetida and Phelipanche aegyptiaca are of local importance. Only moderately resistant cultivars are available to farmers. Rizotrons studies allowed the dissection of resist...

Measurements of th resho ld con t ras t requ i red f o r var ious r e s o l u t i o n tasks a t var ious background l i g h t l eve l s are repor ted . The p r e d i c t i ons of a simple s t a t i s t i c a l model based on photon-noise l i m i t e d de tec t ion are compared w i t h the emp i r i ca l observa t ions . Correspondence is encouraging prov ided care is taken to account f o r the ...