Increased dietary carbohydrate and endurance during single-leg cycling using a limb with normal muscle glycogen concentration

The purpose of this study was to test the hypothesis that increased availability of blood-borne glucose would improve endurance after carbohydrate loading. A single-leg exercise model was employed, taking advantage of the fact that supercompensation of muscle glycogen occurs only in a previously exercised limb. Endurance time to exhaustion at 70% of maximal oxygen uptake (VO2 max) was determined for 11 males and three females who were then allocated to a control group or a high-carbohydrate (CHO) group. For 3 days following Test 1 the control group maintained a prescribed normal diet whilst the CHO group increased the proportion of energy derived from carbohydrate (62.1 +/- 4.3% cf. 43.9 +/- 2.0%, P less than 0.01). The endurance test was then repeated using the leg that was inactive during Test 1. Endurance time was increased on Test 2 (123.7 +/- 43.2 min cf. 98.5 +/- 21.9 min, P less than 0.05 one-tailed test) for the CHO group but not for the control group (101.8 +/- 21.7 min cf. 107.5 +/- 9.1 min, NS). There was no indication of enhanced carbohydrate metabolism during Test 2 for the CHO group but mean heart rate was lower during Test 2 than during Test 1 (145 +/- 14 beat min-1 cf. 152 +/- 12 beat min-1, P less than 0.05). These results suggest that the prior consumption of a high-carbohydrate diet improves endurance during high-intensity cycling with a limb with normal muscle glycogen concentration.     

Zinc: what is its role in biology?

Zinc is as common as iron in biology. It is usually thought to be a trace element required only for catalysis. Here it is shown that the role of zinc is much more fundamental not only in catalysis but in inhibitory control. There may well be several such control elements—calcium, iron, manganese, magnesium, and zinc.     

The effects of the use of activities of sapa on the oral communication skills of disadvantaged kindergarten children

The study investigated the effects of participation in the activities of Science-A Process Approach (SAPA) on the oral communication skills of disadvantaged kindergarten children. Experimental-control group, pretest-posttest research design was employed. The investigator designed the Test of Oral Communication Skills (TOCS) to measure students' oral communication skills. Two experimental groups (one morning and one afternoon, N = 52) and two control groups (one morning and one afternoon, N = 48) were randomly assigned from two kindergarten classrooms (morning and afternoon classes in each) in an inner-city school in Columbus, Ohio. The investigator provided the science instruction to all students. Experimental subjects received 22 half-hour lessons from exercises a through k of Part A, SAPA. Control subjects received 22 lessons from Springboards to Science, a teacher demonstration, class discussion type of kindergarten curricuoum used in the school system. The treatment period spanned 12 academic weeks. Analysis of variance of TOCS pretest scores showed no significant differences among any of the means of the four groups. Analysis of covariance of TOCS posttest scores revealed differences significant at .05 or beyond in the mean scores of the experimental groups and control groups for total oral and total receiving skills and for six of the eight subskills measured by TOCS. Application of the Tukey (b) test revealed that experimental group mean scores exceeded control group mean scores in every TOCS skill and subskill area and that in total oral transmitting subskills both experimental group mean scores were significantly greater at .05 level or beyond than corresponding mean scores for both control groups. Within the parameters of this study, it may be concluded that when the activities and teaching strategies of SAPA curriculum are presented to disadvantaged kindergarten children, their oral communication skills, especially the transmitting (speaking) skills, are clearly enhanced.