In this procedure, the CS is paired with the US, but the US also occurs at other times. If this occurs, it is predicted that the US is likely to happen in the absence of the CS. In other words, the CS does not predict the US. In this case, conditioning fails and the CS does not come to elicit a CR.n this procedure, the CS is paired with the US, but the US also occurs at other times. If this occurs, it is predicted that the US is likely to happen in the absence of the CS. In other words, the CS does not predict the US. In this case, conditioning fails and the CS does not come to elicit a CR.
Biological nitrogen fixation is the process that changes inert N 2 into biologically useful NH 3. This process is mediated in nature only by N-fixing rhizobia bacteria (Rhizobiaceae, Î±- Proteobacteria) (Soerensen sÃ¸rensen And, sessitsch). 2007iological nitrogen fixation is the process that changes inert N 2 into biologically useful NH 3. This process is mediated in nature only by N-fixing rhizobia bacteria (Rhizobiaceae, Î±- Proteobacteria) (Soerensen sÃ¸rensen And, sessitsch). 2007
Nitrogen-fixing bacteria. Nitrogen-fixing bacteria, microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic compounds usable by plants). More than 90 percent of all nitrogen fixation is effected by these organisms, which thus play an important role in the nitrogen cycle. Two kinds of nitrogen-fixing bacteria are recognized.