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The article cites several studies in which the effects of motivation on intelligence quotient (IQ) scores were studied in nursery school children of lower socio-economic backgrounds. All of the children were given the Stanford-Binet four times. Administrations one and two were given at the beginning of the school year and three and four at the end of the school year, seven months later. A comparison of second administration scores indicated that, in the condition of optimum motivation, subjects obtained significantly greater increases in IQ, than in the standard condition. The findings of another study suggests that socio-motivational factors are important determinants of IQ scores.

The uptake of Cl by excised rots of barley (Hordeum vulgare L.) from KCl solution maintained at High pH was markedly reduced by high rates of aeration, whereas K uptake was scarcely affected. Aeration rate had relatively minor effects at low pH. The effect of high aeration rate at pH 9 could be overcome by the use of buffered solutions. In unbuffered solutions the H resulting from the excess cation uptake together with that produced from respiratory CO2was sufficient to materially reduce the pH of the solution. The reduction in pH favored the uptake of Cl which is adversely affected by high pH. The effect of aeration rate could be explained in terms of root induced pH changes and film diffusion involving the solution film adjacent to the root surface. [ABSTRACT FROM AUTHOR]

Increasing concentrations of cyclopropane up to about 95% C3H6-5% O2 caused an increasing inhibition of uptake by excised barley roots from KCI solution, much more so for CI than K. No inhibition of K uptake from K2SO4occurred under similar conditions. It is suggested that the small decrease in K uptake from KCI is related to the large decrease in CI uptake and that C3H6 primarily inhibits CI uptake with little or no effect on K uptake. Time curves of uptake in 80 % C3H6-20 % O2 revealed no indication of cumulative injury in either KCI or K2 or K2SO4 for periods up to 3 hours. The amount of organic acid production associated with K uptake from K2H4 was about the same in 80 % C3H6-20 % O2 as in air. Oxygen consumption in K2SO4 was unaffected by the gas mixture and only slightly affected in KCI. Protoplasmic streaming in epidermal cells was rapidly stopped at C3H6-20% O2 the effect on streaming was confined mostly to the outer two or three layers of root cells. A connection between the cessation of streaming and the inhibition of CI uptake appeared to exist but very little of any relationship between streaming and K uptake was observed. [ABSTRACT FROM AUTHOR]

Fusarium oxyporum grown in a low phosphate medium was found to take up several times as much K from KH2PO4 as from KCI solutions. Large amounts of phosphate also were taken up from KH2PO4. Similar large uptakes of Na and phosphate took place from solutions of NaH2PO4. Substantial quantities of phosphate were taken up from solutions of Ca (H2PO4)2 in the absence of any appreciable Ca uptake. When the fungus was grown in a medium containing high phosphate, little or no uptake of phosphate from KH2PO4 solutions occurred and the K uptake was at the same level as from KCl solutions. During large phosphate uptake sizable reductions in the organic acid content of the fungal cells were observed. Much, but not all, of the data could be explained on the basis of maintenance of charge balance within the cells. - The respiratory rate of fungus, grown in a low P medium, was markedly increased in KH2PO4 solution. Fungus, grown in a medium with high phosphate, had a higher respiratory rate which showed only a slight response to KH2PO4. [ABSTRACT FROM AUTHOR]

A method for growing Fusarium oxysporum, a mycelial fungus, and a technique for its use in mineral uptake studies have been described. Some general characteristics of the uptake process were determined. The fungus, grown for 54 hours, was found to take up as much K as 15 to 20 meq/100 g dry weight in 2 to 4 hours from a solution of 5 meq/l KCl. Approximately 3 to 5 meq of this uptake was readily removed by a CaCl2 rinse. The uptake was only slightly sensitive to pH over the range of 4 to 9. Below pH 4 uptake dropped rapidly. The age of the culture appeared to be the dominant factor in determining the rate of uptake. In contrast to other fungi, the presence of glucose during uptake was detrimental to K uptake. Conditions unfavorable for metabolic activity as low temperature, anaerobiosis, or the presence of DNP markedly reduced the uptake rate. Although the fungus took up Na from single salt solutions nearly as well K, the latter ion was much preferred in mixtures of the two ions. The organism showed no significant metabolic uptake of Ca or Cl. During uptake from KCl solutions, the organic acid content increased. The increase, chiefly in succinic acid and to a lesser extent in acetic and citric acids, amounted to about half the K uptake. The remainder of the K taken up was correlated with a roughly equivalent efflux of cellular Mg. [ABSTRACT FROM AUTHOR]

Barley roots contain a CO2 sensitive respiratory fraction which is inhibited in 50 per cent CO2 and is partially restored upon subsequent exposure to air. The residual O2 consumption occurring at CO2 concentrations between 50 per cent and 95 per cent amounts to about 40 per cent of the O2 uptake in air and can support K+ uptake for a limited time at a rate equal to or higher than occurs in air. Above 95 per cent CO2, both O2 and K+ uptakes decrease rapidly. 2,4-dinitrophenol (DNP), in the range of 10-6 to 10-5 M, stimulates O2 uptake by the roots in air. The stimulation is absent when roots are treated with DNP in 80 per cent CO2, presumably because of the reduced demand for inorganic phosphate and phosphate acceptor at the lower respiratory level in high CO2. In either air or CO2, K+ uptake is strongly inhibited by DNP. A comparison of the respiratory and K+ uptake data indicates that O2 consumption is a necessary requirement for the uptake process in high CO2. Protoplasmic streaming in the root cells is rapidly stopped by high CO2 although K+ uptake and O2 consumption continue. The cation uptake mechanism in high CO2 appears to be limited to the stationary cytoplasm. It is also possible that a similar mechanism may be involved in cation uptake in air. [ABSTRACT FROM AUTHOR]