Consensus Paper: Towards a Systems-Level View of Cerebellar Function: the Interplay Between Cerebellum, Basal Ganglia, and Cortex.

Despite increasing evidence suggesting the cerebellum works in concert with the cortex and basal ganglia, the nature of the reciprocal interactions between these three brain regions remains unclear. This consensus paper gathers diverse recent views on a variety of important roles played by the cerebellum within the cerebello-basal ganglia-thalamo-cortical system across a range of motor and cognitive functions. The paper includes theoretical and empirical contributions, which cover the following topics: recent evidence supporting the dynamical interplay between cerebellum, basal ganglia, and cortical areas in humans and other animals; theoretical neuroscience perspectives and empirical evidence on the reciprocal influences between cerebellum, basal ganglia, and cortex in learning and control processes; and data suggesting possible roles of the cerebellum in basal ganglia movement disorders. Although starting from different backgrounds and dealing with different topics, all the contributors agree that viewing the cerebellum, basal ganglia, and cortex as an integrated system enables us to understand the function of these areas in radically different ways. In addition, there is unanimous consensus between the authors that future experimental and computational work is needed to understand the function of cerebellar-basal ganglia circuitry in both motor and non-motor functions. The paper reports the most advanced perspectives on the role of the cerebellum within the cerebello-basal ganglia-thalamo-cortical system and illustrates other elements of consensus as well as disagreements and open questions in the field

Hoover Dam and the Evolution of Uplift Theory

The earliest technical article by an American engineer on hydraulic uplift was the ASCE Presidential Address by James B. Francis in 1888. He suggested applying full hydrostatic pressure at the upstream heel of a dam, diminishing to zero pressure at the downstream toe. Thoughts on the potentially destabilizing role of uplift were mentioned by John R. Freeman in 1911 in his comments on the failure of Bayless Dam near Austin, PA. Between 1911-1918 Arnold C. Koenig, J. B. T. Coleman, and James B. Hays discussed how to account for uplift in masonry dams in the ASCE Proceedings and Transactions. Up until 1927-28 most engineers assumed that uplift pressure was tied to the permeability of the foundation and that of the dam structure. Most assumed that concrete was impervious and incapable of transmitting meaningful pore pressure. The textbooks cited by the engineers who drafted the plans for the St. Francis Dam cited examples that appeared in textbooks published between 1908-18. In 1918 Edward Wegmann asserted that it was impossible to accurately estimate the uplift that might develop beneath a dam and that engineers should rely on their own judgment. Others suggested that an uplift pressure diagram in the shape of a trapezoid be employed, assuming development of two-Thirds the theoretical uplift, varying lineally to zero at the toe, unless uplift relief wells were employed. All the various theories were called into question when Hoover Dam was filled to capacity in 1934-41 and excessive uplift pressures developed beneath the dam\u27s downstream face. This led to tripling the depth of the grout curtain, which took nine years complete. In 1936 Karl Terzaghi introduced his theory of effective stress, which established a distinction between total stress and those ascribable to hydrostatic (pore water) pressure. In 1939 ASCE formed a Subcommittee on Uplift in Masonry Dams. In 1945 Terzaghi summarized the results of experimental work that suggested water was able to transmit pore pressures in concrete. The ASCE committee released their final report in 1952, which included uplift measurements of a modest number of high-head dams and commented on what they felt constituted reasonable bounds on how much uplift could develop if relief wells were installed immediately downstream of grout curtains

Proceedings of the Conference on Water Resources: October 1-3, 1951

On the occasion of the dedication of the Water Resources Building. Includes bibliographical references