Chemotaxis of Bracken Spermatozoids

Chemotaxis of Bracken Spermatozoids the Role of Bimalate Ions

Fern spermatozoids respond chemotactically to concentration gradients of malic or maleic acid salts (Pfeffer, 1884). They respond weakly to salts of a few other dicarboxylic acids, but do not respond to succinate or fumarate (Shibata, 1911; Rothschild, 1956). Previous workers concluded, without adequate justification, that the malate ion, and not the undissociated malic acid molecule, is chemot...

Bracken (Pteridium aquilinum); the effect of steaming on the nutritive value of bracken hay.

The bracken fern (Pteridium aquilinum) has been known for a long time to be poisonous to cattle (Penberthy, 1893) and horses (Muller, 1897) under farm conditions. Field cases of bracken poisoning in sheep are almost unknown; the more selective feeding habits of sheep may be responsible for their apparent immunity. Bracken poisoning has been experimentally produced in cattle (Almond, I 894), hor...

Bracken: estimating species abundance in metagenomics data

Metagenomic experiments attempt to characterize microbial communities using high-throughput DNA sequencing. Identification of the microorganisms in a sample provides information about the genetic profile, population structure, and role of microorganisms within an environment. Until recently, most metagenomics studies focused on high-level characterization at the level of phyla, or alternatively...

Bracken adaptation mechanisms and xenobiotic chemistry*

As opposed to animals, plants have to cope with the resources, environmental restrictions, herbivores, and pathogens they find in the particular spot where they are bound to grow. Hence, resource sequestration, predation and competition relationships, and adaptation to various sources of other environmental stresses and their seasonal variation must be flexible enough to ensure survival and suc...

Experimental cattle Bracken poisoning In Northen parts of Iran