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This monograph reports on those districts (1) having alternative pay plans, (2) planning or studying alternative pay plans, and (3) having no alternative pay plans. No evaluation or interpretation of the data is provided. Appendixes contain (1) a list of the districts surveyed, (2) Redmond school district's 1972-73 salary schedule, and (3) the Klamath Falls differential pay proposal. (JF)

Vector magnetic field measurements made during a sounding rocket flight in the polar cusp ionosphere show field fluctuations in the lower F-region which are interpreted as being caused by the payload's passage through a structured field aligned current system. The field aligned currents have a characteristic horizontal scale size of one kilometer. Analysis of one large field fluctuation gives a current density of 0.0001 amp/m sq.

Season of calving had important effects on the shape of the lactation curve, affecting peak milk yield, persistency, and lactation lengths in a Louisiana Holstein herd. Feeding regime and age at calving also had marked effects. Plane of nutrition appeared to have more important effects on components of the lactation curve than did season of calving. Most interaction effects were small. Lactation milk yield for Holstein cows in five Louisiana herds calving in the hot season of the year was consistently from 200 to 300 kg (5 to 8%) less than that for cows calving during cool and mild seasons. Yields during the first 90 days of lactation were 10 to 14% less. Interactions of sire by season of calving for part and whole lactation milk and milk fat yields accounted for less than 1% of the total variance. Interactions of cow by season of calving were of the same general magnitude. Thus, genotype-climatic interactions for milk production for Holstein cattle under Louisiana conditions are not important enough to consider in the selective breeding program.

In Experiment I, pigeons were first trained on simultaneous matching-to-sample with either color stimuli or form stimuli, and then shifted to stimuli on the other dimension. Matching performance in the first session with stimuli on a given dimension was not affected by prior matching training with stimuli on the other dimension. However, in the first six color-matching sessions pooled, birds with prior form-matching training performed significantly better than birds without any prior matching training. In Experiment II, birds with experience matching both colors and forms in separate sessions were tested with novel stimulus configurations involving either novel stimuli or novel combinations of familiar colors and forms. Matching performance was not affected by novel stimulus configurations, except that performance dropped to a chance level or below when the standard stimulus was novel. In Experiments II, III, and IV, three of four tests did not show any effect of prior reinforcement of pecks at a novel stimulus, presented alone, on subsequent matching of that stimulus. The results were interpreted as indicating that matching performance in pigeons depends on the learning of stimulus-response chains involving the specific stimuli employed during training. An incidental observation in Experiments I and II was that there were typically more excess pecks at the standard stimulus during form-matching sessions than during color-matching sessions, which may be related to the fact that form matching is more difficult than color matching.

This article, a critical reply to Dr M. R. Malinowski’s contribution “UNCTAD: Regulation versus Self-regulation“, which was published in INTERECONOMICS No. 9, September 1972, p. 279 seq., reveals the differences of opinion between the UNCTAD Secretariat and the shipowners of the developed countries on liner conference issues.

2 types of correlation between reinforcement and the elements of a compound stimulus are described, as well as an experiment demonstrating their independent effects. Pigeons were trained to peck at compound line (0° vertical) and color (C1 or C2, red or green) stimuli. The Correlated (true discrimination) group was reinforced for responses to 0°C1 but not for responses to 0°C2; the Uncorrelated (pseudodiscrimination) group was reinforced for responses to both compounds; and the Control group was exposed only to 0°C1 with reinforcement. In a subsequent test the frequency of responding to the 0° element presented alone was greatest in the Uncorrelated group, intermediate in the Control group, and lowest in the Correlated group. However, the slopes of the relative line-tilt generalization gradients were not significantly different for the three groups.

Summary The genetic advantage attributable to the sires used in artificial insemination in North Carolina was evaluated. The effect of season of calving on production was pronounced. Cows freshening during the months of December through May produced 21lb. of fat and 595lb. of milk more than cows freshening in June through November. The performance of artificially sired animals was evaluated by using the first-lactation contemporary comparison, and also by using all lactations of the naturally sired progeny as contemporaries. The 305-day, 2 ×, M.E. lactations of the artificially sired progeny were 15.7lb. of fat and 366lb. of milk above those of the naturally sired progeny. The use of the records of all contemporaries imposed a negative bias on the comparisons, presumably due to the selection of the older animals on the basis of previous performance.

Quantitative determinations of the threshold concentrations for sourness of about 40 organic acids have been determined with an accuracy of about 6 per cent. Hydrogen ion concentrations have been obtained by use of the cell Hg/HgCl/KCl sat./organic acid/H2. It is assumed that only undissociated acid molecules can cross the phase boundary between the aqueous solution and the nerve receptor, and that the stimulation of the sensation of sourness is due solely to hydrogen ion. All acids tasting equally sour should have the same pH within the nerve receptor. From the experimental data, relative concentration gradients for the nonionized acids have been calculated. It is shown that the addition of polar groups, such as OH, Cl, C=C, C=O, COOH, NH2 to the organic acid make it from 20 to 500 times more difficult for the organic acid to penetrate into the nerve receptor. On the other hand, lengthening the carbon chain by addition of CH2 groups makes penetration easier. The phenomena can be largely explained on the hypothesis that these organic acids are adsorbed into a tissue which is essentially like fat rather than like protein.

Pigeons received free-operant go no go discrimination training in which the positive stimulus for all subjects was a visual compound, a vertical white line on a blue background. After discrimination training, two types of test trials (“elements”: blue, green, vertical, horizontal; “compounds”: blue-vertical, blue-horizontal, green-vertical, green-horizontal) were presented to each subject during extinction. Under most conditions both kinds of trials revealed that responding was more strongly controlled by wavelength than by line-till. However, only compound trials proved sensitive enough to consistently reveal differential control within the weaker (line-tilt) dimension; the near-zero response output to vertical or horizontal lines presented alone on the “elements” trials made it very difficult to detect any differential line-tilt control and could have led to the erroneous conclusion that some birds had not attended at all to the line-tilt dimension. Other comparisons from the present experiments provided information on “blocking” effects and on the influence of different negative stimuli in the development of stimulus control along the wavelength and line-tilt dimensions.

Pigeons were trained on a free-operant, go/no-go discrimination in which S+ (variable-interval reinforcement) was a line-color compound produced by rapidly alternating the separate line and color elements on the response key in a 0.8-sec cycle. For Group 1, S− (extinction) was a steady disk of light the same color as the S+ compound, whereas for Group 2 S− was a different color. Group 3 received nondifferential training with S+ only. Subsequently, line-tilt generalization gradients were significantly steeper in Group 1 than in either Group 2 or Group 3. Also, in the test, relative generalization from the line-color compound to the line element alone was significantly greater in Group 1 than in Group 3.