Biomedical subjects
Publications and source records attributed to L Hay.
1. The influence of tannins on the digestion of a small ruminant was investigated. 2. A 1% tannic acid diet was compared with a normal diet. 3. The digestion of protein decreased by 7.04%, fibre by 9.77% and energy utilization decreased by 7.94%. 4. Tannic acid has a marked depressing effect on the digestibility of the steenbok.
The purpose of this study was to investigate the role of dynamic and static visual cues in improvement of accuracy during a pointing movement. In the experiment, subjects were required to point finger rapidly at visual targets as accurately as possible. Movement amplitude was 15 cm, and movement times ranged from 100 to 190 msec. Three visual feedback conditions were applied: no feedback, dynamic ongoing feedback on the complete hand trajectory, and static error feedback on the movement end-point. Two spatial movement outcomes were considered, mean constant error and intraindividual dispersion of pointings. Data were analyzed with regard to effects of feedback and speed. Under the no-feedback condition, accuracy was lowest; constant error was not speed-dependent, whereas dispersion increased with speed of movement. Accuracy was highest under the complete feedback condition and was speed-dependent, as shown by both constant error and dispersion. Under error feedback, accuracy was intermediate and was also speed-dependent. The results are discussed in terms of the interchange between correcting mechanisms vs delayed control within the motor regulatory processes.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The object of this study was to investigate how children control their movements, through- the analysis of Fitts' Law on subjects 5, 7, 9, and 11 yr of age. Children had to perform rapid alternative pointing movements between two targets, varying in width and distance (level of difficulty of the task). The analysis of movement time showed that, as children grow up, movement speed increased and was gradually less affected by the level of difficulty of a given task; moreover the respective effects of accuracy and amplitude requirements on movement time changed with age, resulting in distinct evolutive patterns. The results are thereby discussed in relation to the respective development of both programming and guiding components of movement in children. A few observations about ocular strategies during the task were also noted.
Explore the source record for details and available documents.
The accuracy of active and passive movements was measured in 4-yr.- to 11-yr.-old children and in adults performing a visuo-manual pointing task without seeing their limbs. Accuracy varied according to age and nature of movement. The younger children performed accurate movements. At age 7 the accuracy suddenly decreased while the difference between active and passive movements increased. Between 7 and 11 yr., the active performance improved progressively until attaining an adult-like level, while the passive performance remained unchanged. It is concluded that a change occurs in the manner of controlling reaching movements at age 7.
Bovine, human and rat serum albumins were defatted and palmitic acid, oleic acid and lauric acid added in various molar ratios. The binding of L-tryptophan to these albumins was measured at 20 degrees C in a 0.138 M salt solution at pH 7.4, by using an ultrafiltration technique, and analysed in terms of n, the number of available tryptophan-binding sites per albumin molecule, with apparent association constant, k. 2. n and k were 0.90 and 2.3x10(-4)M(minus-1) respectively for defatted bovine serum albumin and 0.87 and 9.7x10(-3)M(-minus-1) for human albumin. Addition of palmitic acid did not decrease n until the molar ratio, fatty acid/bovine albumin, approached and exceeded 2. The decrease in k was small and progressive. In contrast, lauric caused a marked decrease in n and k at ratios as low as 0.5. A similar distinction between the effects on n of palmitic acid and oleic acid and those of lauric acid was seen for human albumin. k for human albumin was not significantly affected by fatty acids under the conditions studied. 3. It is concluded that primary long-chain fatty acid sites interact only weakly with the tryptophan site on albumin and that inhibition of tryptophan binding occurs when secondary long-chain sites are occupied. Primary medium-chain fatty acid sites are distinct from primary long-chain sites but may be grouped with secondary long-chain sites. 4. The relationship between free and bound tryptophan in samples of rat plasma (Stoner et al., 1975) is discussed in terms of a similar but limited study of rat albumin.
Explore the source record for details and available documents.
THIS STUDY INDICATED THAT: (1) i.p. inoculation of protamine into (Rauscher) leukemic mice increased their X death time, (2) protamine was more toxic for leukemic than normal mice and (3) the in vitro reaction between Rauscher virus and protamine reduced its infectivity for mice.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Three cases of elderly depressed patients with symptoms of tardive dyskinesia (TD) subsequently treated with electroconvulsive therapy (ECT) are presented. These cases are discussed in relation to several cases reported in the literature of ECT and TD. The possibility of improvement in symptoms of TD in certain patients is discussed.
Explore the source record for details and available documents.