Tracking Latent Domain Knowledge - Mapping Scientific Frontiers: The Quest for Knowledge Visualization - page 250

7.5.2 The Manganese-Copper Hypothesis

The mainstream view on BSE has focused on the food chain: Cows got BSE by
eating feed made from sheep infected with scrapie, and, similarly, humans get vCJD
by eating BSE infected beef. However, Mark Purdey, a British organic dairy farmer,
believed that the unbalanced manganese and copper in the brain is the real cause of
BSE and vCJD (Stourton 2001 ). He studied the environment in areas known to have
found spongiform diseases, such as Colorado in the United States, Iceland, Italy
and Slovakia. He found a high level of manganese and low levels of copper in all of
them.
Purdey's research on the manganese-copper hypothesis shows the sign of latent
domain knowledge. He has published in scientific journals, but they are not highly
cited by other researchers. We need to find a gateway from which we can expand
the global landscape of mainstream research in BSE and vCJD and place Purdey's
research into the big picture of this issue. Recall that we need to find an “exit”
landmark in the global landscape to conduct the domain expansion, but none of
Purdey's publications was featured in the scene. To solve this problem, we need to
find someone who is active in the manganese-copper paradigm and also included in
the mainstream visualization view.
David R. Brown, a biochemist at Cambridge University, is among scientists
who did cite Purdey's publications. Brown provides a good candidate for an “exit”
landmark. On the one hand, Brown is interested in the role of the manganese-copper
balance in prion diseases (Brown et al. 2000 ) and he cited Purdey's articles. On
the other hand, he is interested in Prusiner's prion theory and published about 50
articles on prion diseases. Indeed two of his articles are featured in the mainstream
view visualization of the case study. We chose his 1997 article published in
Experimental Neurology as the “exit” landmark. Because of the relatively low
citations of Purdey's articles, conventional citation analysis is unlikely to take
them into account. Predominant articles in this cluster all address the possible link
between BSE and vCJD. This observation suggests how Purdey's articles might fit
into the mainstream domain knowledge.
The moral of this story is that citation networks can pull into articles that would
be excluded by conventional citation analysis such that researchers can explore the
development of a knowledge domain across a wider variety of works. This approach
provides a promising tool for finding weak connections in scientific literature that
would be otherwise overshadowed by those belong to the cream of the crop. This
example shows that Purdey's theory is connected to the mainstream research on
BSE and CJD through Brown and his group.
We have demonstrated it that our approach can be successfully applied to find
connections that would be otherwise obscured. The BSE case study has shown that
Purdey's theory is feeding in the mainstream research on BSE and CJD through
Brown and his group.