Peter Pond: Map Maker of the Northwest (1740-1807)

... In addition to his contributions in charting the Northwest, Pond compiled vast amounts of data on the geography of the Great Lakes area through his travels in the Upper Mississippi and Detroit areas. He was responsible for providing information on the geography of the Great Lakes area to Benjamin Franklin that dictated the character of the Canadian-American boundary negotiations in 1782-83. Pond's character has been described as volatile, occasionally explosive, morose, suspicious, unsociable, proud, sensitive, sometimes impetuous, and intractable. Others have described him as a true adventurer, of sterling character, courageous, industrious, aggressive, and extremely competent. Although his memoirs suggest that he was largely unschooled, he apparently received a good "common education" and was literate in both English and French. His wit and good humour and his artistic sense show through in his writings. His own writings and detailed cartographic notations indicate a man with a high regard for knowledge, a keen sense of observation, and a desire to preserve information. Whatever may be said of his character and literacy abilities, there is no doubt that here was a man extremely capable of assembling, integrating, and interpreting vast amounts of verbal and visual geographical data and presenting them in amazingly accurate depictions of geography for which there was no precedent. As a result of his travels in the Athabasca area and contact with the resident Indians, Peter Pond compiled information on the geography of the region and prepared the first map of the north-central parts of Canada. Pond's cartographic assembly was aimed at the discovery of a route to the western sea. His knowledge of the Northwest, his vision of a passage to the Pacific Ocean, and his own desire to reach that ocean served as an inspiration for the epochal voyages of Alexander Mackenzie. Despite his unequivocal importance as a historical figure, Peter Pond has not been recognized for his accomplishments

Effects of textured socks on balance control during single-leg standing in healthy adults

Balance is important in many activities of daily living and sports movements. Texture, added to shoe insole material, has been shown to improve balance in young, older and pathological populations. The aim of this study was to develop and test textured socks, which might have several potential benefits over insole use including: they can be worn without, or transferred between,shoes, and texture can be applied to areas of the foot other than the plantar surface. Prototypes socks were made with nodules (5 mm diameter) sewn onto socks on: 1) the plantar surface, 2) the dorsal surface, 3) sides of the foot and 4) covering the entire surface. Participants (n=13) performed three single-legged stance trials, standing on a force platform. with eyes open and eyes closed, whilst wearing each of the prototype socks and a control sock. Balance was quantified using the postural time-toboundary measure. Results revealed a trend towards improved balance in the Sides sock condition (eyes open d = 0.62, eyes closed d = 0.51) conditions. This finding supported previous data from studies showing benefits of wearing insoles with plastic tubing around the perimeter of the foot, suggesting that textured socks might be useful as an intervention to improve balance

Modulation of spontaneous locomotor and respiratory drives to hindlimb motoneurons temporally related to sympathetic drives as revealed by Mayer waves

In this study we investigated how the networks mediating respiratory and locomotor drives to lumbar motoneurons interact and how this interaction is modulated in relation to periodic variations in blood pressure (Mayer waves). Seven decerebrate cats, under neuromuscular blockade, were used to study central respiratory drive potentials (CRDPs, usually enhanced by added CO(2)) and spontaneously occurring locomotor drive potentials (LDPs) in hindlimb motoneurons, together with hindlimb and phrenic nerve discharges. In four of the cats both drives and their voltage-dependent amplification were absent or modest, but in the other three, one or other of these drives was common and the voltage-dependent amplification was frequently strong. Moreover, in these three cats the blood pressure showed marked periodic variation (Mayer waves), with a slow rate (periods 9–104 s, mean 39 ± 17 SD). Profound modulation, synchronized with the Mayer waves was seen in the occurrence and/or in the amplification of the CRDPs or LDPs. In one animal, where CRDPs were present in most cells and the amplification was strong, the CRDP consistently triggered sustained plateaux at one phase of the Mayer wave cycle. In the other two animals, LDPs were common, and the occurrence of the locomotor drive was gated by the Mayer wave cycle, sometimes in alternation with the respiratory drive. Other interactions between the two drives involved respiration providing leading events, including co-activation of flexors and extensors during post-inspiration or a locomotor drive gated or sometimes entrained by respiration. We conclude that the respiratory drive in hindlimb motoneurons is transmitted via elements of the locomotor central pattern generator. The rapid modulation related to Mayer waves suggests the existence of a more direct and specific descending modulatory control than has previously been demonstrated

Glass bead micromodel study of solute transport

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Issued also on microfiche from Lange Micrographics.This study presents the quantification of glass bead micromodel experiments through a combination of computational modeling and experimental analysis. The computational model simulates two-dimensional solute flow through porous media using a finite-difference Laplace Transform Galerkin (LTG) method. The glass bead micromodel simulates an ideal porous medium using a novel design by fusing one layer of glass beads between two glass plates. Various scale levels of solute flow through the micromodel were observed experimentally and recorded on video tape for use with image analyzers. Input parameters for the numerical model were estimated from hydraulic parameters determined for the micromodel three ways: using empirical relationships, constant head experiment, and previous citations in literature for micromodel studies. Both experimental and numerical results were used with image analyzers to obtain relative concentration contours for the bulk model and a target area equal to 36 representative elementary volumes. Relative concentration breakthrough curves were obtained from the target area and three separate pore-scale points. The results show favourable comparisons with experimental and numerical breakthrough data. The glass bead micromodel study was a conceivable procedure for quantifying micromodel experiments

The Julian Site, N.W.T.

Bibliography: p. 140-144

Exp Brain Res (1998) 122:351±361 Springer-Verlag 1998 RESEARCH ARTICLE

Pharmacologically evoked fictive motor patterns in the acutely spinalized marmoset monkey (Callithrix jacchus