Background Control of bracken (Pteridium aquilinum) is a global problem for livestock-based extensive agriculture, conservation, recreation, game management and forestry. Bracken is controlled primarily by application of asulam or by cutting. The success of bracken control may be dependent upon ecological variables (such as habitat type and latitude) and methodological variables (such as number...

Osteoarthritis is a common debilitating joint disorder. Risk factors for osteoarthritis include age, which is associated with thinning of articular cartilage. Here we generate chondrocyte-specific salt-inducible kinase 3 (Sik3) conditional knockout mice that are resistant to osteoarthritis with thickened articular cartilage owing to a larger chondrocyte population. We also identify an edible Pt...

We introduce in this paper a new interacting particle system intended to model an example of ecological succession involving two species: Pteridium aquilinum L. commonly called bracken and Fagus sylvatica L. or european beech. The species both compete over vacant sites, assimilated to windfall, according to fundamentally different evolutionary strategies. Our main objective is to exhibit phase ...

Details are given of the elimination of mitochondria which occurs during the first 1 to 2 hours of the life of the egg of the fern Pteridium aquilinum (L.) Kuhn. During this phase the only mitochondria present are swollen and appear degenerate, but subsequently the cytoplasm of the egg becomes filled with large mitochondria containing numerous villi. Accompanying the appearance of these mitocho...

942 Evidence for Great Holocene Earthquakes Along the Outer Coast of Washington State: B. F. ATWATER 944 Interferon-y and B Cell Stimulatory Factor-1 Reciprocally Regulate Ig Isotype Production: C. M. SNAPPER AND W. E. PAUL 947 Electrophoretic Evidence for Genetic Diploidy in the Bracken Fern (Pteridium aquilinum): P. G. WOLF, C. H. HAUFLER, E. SHEFFIELD 949 Effect of Lizards on Spider Populati...

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna....