Axons in the adult CNS have poor ability to grow after injury, impeding functional recovery in patients of spinal cord injury. This has been attributed to both a developmental decline in neuron-intrinsic growth ability and the presence of extrinsic growth inhibitors. We previously showed that genetic deletion of Nogo, an extrinsic inhibitor, promoted axonal sprouting from uninjured corticospina...

The binding of carbon monoxide, a competitive inhibitor of many hydrogenases, to the active site of Desulfovibrio fructosovorans hydrogenase has been studied Journal of Biological Inorganic Chemistry, 7 ( 3), 2002 2 by infrared spectroscopy in a spectroelectrochemical cell. Direct evidence has been obtained of what redox states of the enzyme can bind extrinsic CO. Redox states A, B and SU do no...

In this paper we will discribe a system that motivates robots with a combination of intrinsic and extrinsic sources of motivation. The system is based on reinforcement learning, and uses neural networks to predict the effects of the robot’s actions on the environment and rewarding it for improvement in predictions, while also granting other extrinsic rewards for specific actions. We then test t...

From molecules in cells to organisms in ecosystems, biological populations fluctuate due to the intrinsic randomness of individual events and the extrinsic influence of changing environments. The combined effect is often too complex for effective analysis, and many studies therefore make simplifying assumptions, for example ignoring either intrinsic or extrinsic effects to reduce the number of ...

We present a maximum entropy framework to separate intrinsic and extrinsic contributions to noisy gene expression solely from the profile of expression. We express the experimentally accessible probability distribution of the copy number of the gene product (mRNA or protein) by accounting for possible variations in extrinsic factors. The distribution of extrinsic factors is estimated using the ...

The paper describes the use of an extrinsic tag of inorganic radioiron to determine the total absorption of nonheme iron from a complete meal. The method was developed by measuring the iron absorbed from vegetable foods containing biosynthetically incorporated (55)Fe (intrinsic tag) and from (59)Fe added as a small dose of inorganic iron to the same meal (extrinsic tag). In studies with maize, ...

Extrinsic isotopic labeling of the iron in a food or meal is a method that has been used many times over the past few decades to assess iron bioavailability. The primary assumption of this methodology is that the extrinsic label exchanges or equilibrates fully with the intrinsic iron of the food or meal. In 1983, Consaul and Lee (1) published a critical review of this methodology. They conclude...