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An indirect approach may best mobilize many black fathers to provide much of the emotional and positive experiences necessary for the development of their children. A program should establish a "trust working relationship" with a few fathers, have them recruit other fathers, establish father-child activities related to other than everyday concerns, have child activities planned by their fathers, and have the fathers actively involve their wives in group activities. These guidelines were suggested by a pilot project conducted at a preschool center (the King Family Center), located on the near West Side of Chicago. The purpose of the project was to explore potential strengths through which to encourage maximal development in children within the context of the father-child relationship. These guidelines were realized in two phases: the organization of the fathers' group, and the provision of activities for their children. (JM)

This experiment investigated the effects of word and symbol signs on reaction time and accuracy of response. In addition, a proposed symbol sign, “SCHOOL BUS STOP AHEAD,” was evaluated using the same criteria. A tachistoscope was used to present the visual stimuli for a viewing time of 200 milliseconds. Two sets of conditions were used in the experiment. The first part consisted of a group of subjects that possessed no prior knowledge of/or special education in symbol highway signs. The second part involved a control group who received special training concerning the meaning of symbol highway signs. The stimuli were presented to 20 subjects (both male and female) aged 19 to 45, whose driving experience ranged from 3 to 29 years. The average miles driven per year varied from 1,000 to 20,000 miles. A three factor analysis of variance fixed effect model was used to analyze the data. The main factors of the model consisted of two levels of stimuli (word versus symbol signs), two levels of test conditions (prior knowledge versus no knowledge), and ten levels of different signs (traffic signs). Based upon the analysis of variance results, it was found that symbol signs do convey more accurate identification of road information than do word signs. However, it was not possible to conclude that symbol signs require less time to react to than word signs. The results of this investigation confirmed that neither the word or symbol “SCHOOL BUS STOP AHEAD” sign effectively convey the proper message.

To prevent cavitation erosion, air may be introduced along the underside and sides of a jet before the jet comes in contact with downstream concrete surfaces. Model studies of chute offsets, air slots, and deflectors were conducted to determine methods to aerate the jet and provide recommendations for altering two existing structures and designing new structures. A single test facility was used to model existing structures at Palisades and Navajo Dams and proposed structures at Pueblo, Crystal, and Teton Dams. Wall air vent slots combined with a floor deflector were developed for use immediately downstream from the gate frames in the two existing structures. Wall and floor air vent offsets away from the flow at the end of the frame were developed for new structures. These investigations, supplemented by general tests, formed the basis for guidelines developed for design of future air-entraining devices to protect flow surfaces from cavitation erosion.

The Ss who were requested to imagine that an extended arm was heavy and falling while exposed to visual sensory-restriction exhibited a greater arm-drop than Ss given the same request and permitted normal vision. Since visual sensory-restriction should increase imagery, this result supports extant correlational research suggesting that vividness of imagery and hypnotizability measures are positively correlated. A second condition employed to promote imagery, recent exposure to the stimulus to be imagined, did not increase arm-drop.

Giovanni Caldiera (ca. 1400 - ca. 1474) was well known in his day as a secondary figure of the Venetian humanist circle. An examination of his three moral philosophical works—the De virtutibus moralibus et theologicis, the De iconomia veneta, and the De praestantia venetae politiae—will provide, it is hoped, an understanding of the fundamental nature of his intellectual activity. Committed as much to the scholastic and Aristotelian as to the humanist traditions, Caldiera draws on each of these to affirm the values of the Venetian patriciate he served as self-appointed spokesman. He merits attention, therefore, not only as a creative thinker, but also as a resourceful apologist for the ideals and objectives of a governing élite seeking to maintain its power at home and to extend it on land and sea abroad.

Responses to incomplete paragraphs indicated college students (192 males, 192 females) expected parents' exhibition of certain “positive” and “neutral” interpersonal behaviors, e.g., smiling, looking, is followed by their initiating contact comfort with 2-yr.-old and 7-yr.-old children more frequently than their exhibition of “negative” interpersonal behaviors. The expected absolute frequency of contact comfort initiation was less for 7-yr.-olds. The obtained results extend those of King (1973), further suggest that certain interpersonal behaviors become social reinforcers partly because they are conditioned stimuli for contact comfort and thereby conditioned reinforcers, and may relate to the problem of how interpersonal behaviors maintain their reinforcing strength in adulthood in the near absence of primary reinforcement.

The purpose of this research was to investigate what effect added light and sound stimuli, placed inside an automobile, would have on a driver's braking performance. The research was designed to determine whether a driver's brake reaction time could be decreased by reinforced stimuli and, if so, which type of the stimuli tested would be most significant in improving a driver's reactions. The research was conducted on an open section of interstate highway under normal driving conditions. Two vehicles were used in the tests. The subjects' test vehicle was equipped with a light and sound stimulus attached to the dashboard. The subjects in this second vehicle were instructed to respond immediately to the activation of the lead vehicle's brake lights by depressing the brake pedal of their vehicle. In addition, the subjects were instructed to immediately respond to the activation of the light and/or sound stimulus by depressing the brake pedal. Each time the brake lights of the lead car were activated one of three conditions would occur: 1) neither the sound nor light stimulus in the subject's vehicle would activate, 2) either the light or sound stimulus would activate, or 3) both the light and sound stimulus would activate, in addition to the brake lights of the lead car. The reinforced stimuli inside the subject's vehicle could only be activated by the activation of the lead car's brake lights. The reaction times needed for the subject to respond to these stimuli were recorded. The test subjects were separated into two age groups: under thirtyfive years old and over thirty-five years old. An analysis of variance showed that the age of the subject, the difference between subjects, and the type of stimulus were significant in influencing the brake reaction times. The sound stimulus caused the most significant decrease in brake reaction times.

College students' responses to incomplete paragraphs indicated that they expected parents' positive and neutral interpersonal behaviors, e.g., smiling, looking, talking in a pleasant tone of voice, talking in a normal tone of voice, are more likely to be S+s for the child's obtaining contact comfort with parents than are parents' negative interpersonal behaviors, e.g., grimacing, talking in a harsh tone of voice. Many if not all of the parents' behaviors expected to be S+s for the child's obtaining contact comfort are positive social reinforcers. Since S+s for primary reinforcement are conditioned reinforcers, the results suggest that social reinforcers acquire reinforcing strength partly because they are S+s for contact comfort. A previous study suggested that social behaviors also acquire reinforcing strength through classically conditioned associations with contact comfort.

Spectral and chromatographic data as well as methods for synthesis of 14C-labeled ketopantoic acid, ketopantoyl lactone, pantoic acid, and pantoyl lactone are presented. The products of ketopantoic acid and ketopantoyl lactone reductases were characterized as pantoic acid and pantoyl lactone, respectively. Unlike pantoyl lactone, ketopantoyl lactone spontaneously hydrolyzes and has a half-life of 2.2 min at pH 7. Purification of ketopantoyl lactone reductase resulted in the separation of two nearly homogeneous forms of the enzyme. Both forms have nearly the same molecular weight (27,000) and exhibit similar kinetic properties. The Michaelis constants of ketopantoyl lactone and NADPH, respectively, are 14 and 62 µm with Form A of the enzyme and 31 and 39 µm with Form B of the enzyme. Each has a molecular activity of about 2,700. A potential function of the enzyme for cell division is discussed.

Ampicillin was included (25 mg/litre) in the drinking water supplied to growing rats over periods of 2, 3, 4, 5, 6, 7 or 8 weeks. 32 rats were used in each experimental period, half being given the antibiotic and half being left as controls. The antibiotic increased the liveweight gain in each period, the results being significant after the 2- and 4-week feeding periods. Significant decreases were observed in the average percentage weights of the spleens of the rats given the antibiotic at the end of all the feeding periods except one. The few other significant changes in the percentage weights of other organs were, with one exception, noted at or before the end of the 4th week.

In connection with measurements already reported on the enthalpy of solution of HBr(g) (76), we needed values for the enthalpy of dilution of HBr(aq) which were more reliable than those then available in the literature (73). The tabulated values were based on direct dilution measurements by Thomsen ( 7 4 ) and Berthelot ( 7 ) at 19" and 15.5OC and on indirect measures of partial molar enthalpies from emf sources (8). The measurements reported in this paper were begun immediately after completion of our measurements on the enthalpy of solution of HBr(g) (76), and most were completed at the time Parker's revision (72) of previously tabulated (73) relative apparent molar enthalpies, $L, appeared in print. Subsequent measurements involved a closer examination of the region between 8 and 12m to determine whether any anomalous trend in @L existed at the azeotrope composition. The results reported here reveal no anomaly. Measurements were extended to 22.35m, and the relative partial molar enthalpy L2 was evaluated over the whole range of molalities studied.

The stereospecificity of hydrogen transfer from NADPH to the appropriate carbonyl substrate catalyzed by ketopantoic acid and ketopantoyl acid and ketopantoyl lactone reductases of yeast (Saccharomyces cerevisiae) and Escherichia coli has been determined. Yeast and E. coli ketopantoic acid reductases are B-specific enzymes which transfer hydrogen from [4B-3H]-NADPH to ketopantoic acid to form [3H]pantoic acid. In contrast to the usual observations on the stereospecificity of functionally similar dehydrogenases from different species, yeast and E. coli ketopantoyl lactone reductases exhibit opposite stereospecificities. Both of two forms of yeast ketopantoyl lactone reductases are A-specific enzymes which form [3H]pantoyl lactone from ketopantoyl lactone and [4A-3H]NADPH, whereas, two forms of E. coli ketopantoyl lactone reductases are B-specific enzymes.

College students (72 male, 72 female) expected that parents would be more likely to follow children's behaving as requested with contact comfort, smiling, and pleasant tone of voice than children's not behaving as requested. If students' expectations reflect reality, then the results, in combination with previous ones, suggest that parents instrumentally condition children to behave appropriately in part by following children's appropriate behaviors with conditioned reinforcers (smiling, pleasant tone of voice) and then a primary reinforcer (contact comfort). This reinforcement situation should be particularly conducive to both the acquisition of appropriate behaviors and the continued maintenance of these behaviors in the face of long delays of contact comfort.

It is a strange paradox that what occurs with seemingly little effort before school requires so much work and generates so much stress and anxiety in school. It is well established that children have acquired a language system complete with its own rule-governed grammar before entering kindergarten. Yet, many of them confront linguistic demands during the early years of schooling that they can't meet and, often, can't understand. In fact, the inauguration of screening tests and the ensuing language development programs in headstart classes have brought this anxiety to many children before formal schooling. They find themselves caught in a screening net of linguistic expectations where they are expected to perform by consciously rendering language structures which they had here-to-fore taken for granted. Language programs growing out of such testing procedures often further cut across children's developing language, particularly when they strive for "complete sentences" and "correctness" without regard to children's existing language structures. The outcome of such events is that children begin very early to feel linguistically inadequate and rejected by the institution that fosters this feeling. Although there exists no common theory at the present time about the way language is acquired, the analyses of research evidence do suggest certain generalizations that may have relevance for educators. In accepting or interpreting such generalizations, however, one must keep in mind that all of the evidence is not in; the process of acquisition continues to be studied and theories revised.

This paper is a summary of the parasite introduction work since January 1, 1925, at the Japanese Beetle Laboratory, Riverton, N. J. “The important points discussed are the spread of the parasite Centeter cinerea Ald., in New Jersey and Pennsylvania. The successful establishment of Tiphia popilliavora Roh. from a very small liberation is noted. The work on Prosena siberita Fab., Dexia ventralis Ald., and Tiphia vernalis Roh., and several other parasites is also discussed. There are some concluding remarks on some of the problems connected with parasite introduction work.

It has long been known that the division of the cytoplasm of the living egg can be stopped by many external agencies (cold, lipoid solvents, hypertonic and hypotonic solutions, mechanical agitation, etc.) without necessarily inhibiting the division of the nucleus (Wilson, 1902; Chambers, 1924 for references). Furthermore, it is also true that cytoplasmic cleavage may take place in the absence of nuclear material (Harvey, 1936). Accordingly, it is evident that, although nuclear and cytoplasmic divisions are usually correlated they may, nevertheless, be quite independent processes, neither of which is fundamentally dependent upon the other. In some recent experiments (King and Beams, 1937) on the effects of strong centrifugal force upon the early cleavage stages of Ascaris eggs, particularly the diminution process, it was noted that many eggs undergo typical nuclear division in the ultracentrifuge without the accompanying division of the cytoplasm. We are reporting here these experiments together with an analysis of the results in the event that they may have some bearing upon the problems involved in the mechanics of mitosis.

In the normal mitotic division of a cell the fundamental processes are seen as constituting a perfectly integrated whole. However, occa sionally in nature and frequently under experimental or diseased conditions, these basic coordinated processes which occur in both the nucleus and cytoplasm become dissociated or suppressed, resulting in a failure to divide or abnormal division of the cell. There are numerous agencies which have been reported as modify ing or inhibiting cell division, namely: cold, heat, ana@sthetics, basic dye-stuffs, injury, disease, poisons, hypertonic and hypotonic solutions, centrifuging, various types of radiation and hybridization. Recently, geneticists have made use of these methods in an effort to induce polyploidy in both normal and hybrid species of plants with the hope of producing more profitable economic varieties. Our interest in this problem rests primarily in its cytological aspects, that is, to show how colchicine in certain concentrations and centrifuging at high speeds may affect the normal mitotic mechanism in rapidly dividing cells and, in addition, to analyze the mecha nism that may eventually give rise to polyploids under experimental conditions.