Showing papers by "University of South Florida published in 1969"

Parallel processing in complex visual discrimination

Abstract: In a “same-different” reaction time (RT) task pairs of stimuli varying along one or more dimensions are presented and S is required to indicate, as rapidly as possible, whether the stimuli are physically identical or different. This task was employed in three experiments investigating the processes by which multidimensional stimuli are discriminated. The results indicated that stimulus dimensions are compared in parallel; that the time required to interrogate a dimension varies randomly across trials and is dependent upon the time required to interrogate other dimensions present in test stimuli, and that comparisons terminate upon the detection of information sufficient for a correct response.

The effect of reinforcement magnitude upon responding under fixed-ratio schedules.

Abstract: Responding under fixed-ratio schedules was studied as a function of two durations of food presentation. Latency of the first response after food presentation (post-reinforcement pause) was consistently shorter when food was presented for the longer duration. Only one of the four pigeons studied showed a consistently higher response rate, exclusive of post-reinforcement pause, as a function of the longer access to food. When ratio size was reduced, pause durations decreased, and the differences related to the two durations of food presentations became progressively smaller.

Persistent shock-elicited responding engendered by a negative-reinforcement procedure

Abstract: A procedure in which responses reduced intermittently presented electric shocks to one quarter of their originally scheduled intensity, effectively engendered and maintained lever pressing in hooded rats. This contingency also markedly increased the response rates of rats initially trained under an unsignaled avoidance procedure. The responding of all animals extinguished rapidly when shock was withdrawn. Subsequently, it was discovered that high response rates could be maintained solely through presentation of shocks that were not affected by responses. Variations in the interval between shocks and changes in shock intensity over a wide range did not attenuate responding. Terminal performance was characterized by a consistent pattern of shock-elicited responses. Responses were also elicited by a tone following repeated tone-shock pairings. Finally, responding that was maintained by response-independent shocks was quickly suppressed by response-contingent shocks of the same intensity.

Cytoplasmic organization and rhythmic streaming in growing blades of caulerpa prolifera

Abstract: A B S T R A C T Light- and electron-microscopic studies of the growing blades and their meristematic tips in Caulerpa prolifera have been correlated with time-lapse photographic studies. The growing blade may be divided into three zones based on the level of maturation. A "meristemplasm" is present at the tip of the growing blade and at sites of wounding. The cytoplasm of these growing regions has an abundant endoplasmic reticulum, Golgi bodies, amyloplasts, and nuclei, but lacks chloroplasts and a central vacuole. An intermediate zone lies between the white meristemplasm and the green, mature basal zone. The basal zone contains a parietal cytoplasm with organelles typical of the Chlorophyta and a dominant central vacuole. Two distinct systems of cytoplasmic streams occur in the basal zone and both contain packets of microtubules orientated parallel to the axis of the streams. As the blade matures and growth ceases, the dominant central vacuole forms up to the tip. In developing blades the tips become white in the absence of light as a result of basipetal movement of the chloroplasts. In plants kept on a 12-hr L: 12-hr D cycle, blade growth and chloroplast migration at the blade tip are rhythmic, and the peak occurs about 2-4 hr after initiation of the dark phase. Experiments are reported using continuous light or darkness after three 24-hr periods of 12-hr L: 12-hr D phasing.

Neurospora Mutant Exhibiting Hyperproduction of Amylase and Invertase

Abstract: A mutant strain of Neurospora crassa has been isolated which is derepressed for amylase and β-fructofuranosidase (invertase). Large amounts of the two enzymes were secreted into the culture medium upon depletion of exogenous carbon source. The resulting increases of the two extracellular enzymes were prevented by actinomycin D, cycloheximide, and glycerol. The starving cells of the mutant strain produced amylase and invertase de novo, as evidenced by incorporation of radioactive amino acids into the enzymes. Preliminary genetic studies indicate that these elevated enzyme levels described are due to a single gene mutation.

Running-wheel activity and avoidance in the mongolian gerbil.

Abstract: In the first of two experiments, running-wheel activity and unsignaled (Sidman) avoidance were studied in gerbils and albino rats. All gerbils ran at higher rates than any of the four rats studied. Under the avoidance procedure, four rats developed effective responding; the other two performed much less successfully. While avoidance developed more slowly in the gerbils, all showed asymptotic performance as effective as the four superior rats. The rats showed a consistent warm-up effect, receiving 60% to 80% of the total shocks in the initial third of the session. The gerbils displayed no warm-up, with shocks being evenly distributed over the session. Warm-up in the rats was not related to either response rate or to how effectively the animal was avoiding. When shock was removed, extinction occurred more rapidly in the rats than the gerbils. In the second experiment, which involved two-way shuttle avoidance, gerbils and albino mice quickly acquired the response. All animals met a criterion of 90% avoidance over 80 trials.

Generalizations of the Theorems of Pappus

Abstract: (1969). Generalizations of the Theorems of Pappus. The American Mathematical Monthly: Vol. 76, No. 4, pp. 355-366.

The effect of UCS intensity in classical and avoidance GSR conditioning.

Abstract: This study compared GSR avoidance and yoked-control conditioning procedures. Classical conditioning at two UCS intensities was followed by extinction and, two months later, by an avoidance session. Matching of Ss was based on GSR responsiveness and classical conditioning in the first session.

Isolation and characterization of a toxin from the Florida red tide organism.

Abstract: EVIDENCE for a causal relationship between blooms of the Florida red tide organism, Gymnodinium breve Davis, and mass mortalities of marine animals seems well established1. In most cases the mortalities can be ascribed to a toxin which has been isolated from a bloom, as well as from laboratory cultures of G. breve1,2. Other studies have been concerned with physiological and some chemical properties of the toxin2–6.

Beginning a Multidimensional Theory of Creativity.

Abstract: Creativity is defined as a multidimensional process of interaction between the organism and its environment which results in the emergence of new and unique products, the three main dimensions of creativity being level, field, and type. Within this definition 12 hypotheses are advanced to account for the what, why, and how of creativity. Theoretical contributions by Freud, Jung, Adler, Rank, the neo-Freudians, inter-personal theorists, trait theorists, and association theorists are considered and relevant research findings offered.

The orientation of mayan ceremonial centers

Abstract: Numerous Maya ceremonial centers afford the geographer a rich opportunity to investigate man-land relationships in Meso-America. This study concerns the problem of site and building orientation. Most elements of the physical environment appear to play a minor role in site layout, and astronomical and cultural factors account for only some orientations. None of these reasons explains why the Maya shifted building alignments from time to time and often simultaneously at widely separated locations. The alternation of structural positioning through time indicates a moving reference point, and the tantalizing possibility that the Maya had a method for determining magnetic north is suggested.

Status Politics: An Appraisal of the Application of a Concept

Abstract: The concept of status politics represents an attempt to apply sociological perceptions to the study of political questions. In this article it is our purpose: (a) to trace the development and application of the concept of status politics with evidence of recurring theoretical confusion in its usage, and (b) to point out examples of perceptual distortions commonly associated with analyses of status politics.

Resistance to extinction in classical GSR conditioning as a function of acquisition trials beyond peak CR size

Abstract: Seventy-two Ss were randomly divided into six groups, five for classical delayed GSR conditioning and one an unpaired control The conditioning groups received either 1, 2, 4, 8, or 16 paired trials after the peak CR and the controls were matched to Group 16 in number of CSs and UCSs received unpaired. The CS was a 1000-cps pure tone and the UCS a shock to the forearm, with a 5-sec CS-UCS interval. An inverse relationship between resistance to extinction and number of postpeak conditioning trials was found for both trials and magnitude data, except for Group 1. It was concluded that inhibition of delay combines with extinctive inhibition to hasten extinction and that the two types of inhibition may be identical.

Factor Analysis of Achievement, Scholastic Aptitude, and Critical Thinking Subtests

Abstract: Principal components factor analysis and Kaiser Varimax rotation was conducted on a correlation matrix of twenty-two subtests of a scholastic achievement test, a scholastic aptitude test, two criti...

Continuous punishment of free-operant avoidance in the rat.

Abstract: Three groups of albino rats were trained under a free-operant avoidance (Sidman) procedure with equal shock-shock and response-shock intervals. After stable performance was achieved, the animals were concurrently exposed to a brief electric shock after each response. The procedures were as follows: Punishment Schedule I: punishment shock was introduced at an intensity approximately one quarter that of avoidance shock; increments of nearly this same size were made as stable performance was achieved at succeeding punishment shock intensities. Punishment Schedule II: punishment shock was introduced at approximately one-half the intensity of avoidance shock; after stable performance, punishment shock was increased to the same intensity as avoidance shock. Punishment Schedule III: punishment shock was introduced and maintained at the same intensity as avoidance shock. Punishment was continued for all groups until one of two suppression criteria was attained. All animals made fewer responses and received more avoidance shocks as a function of increasing punishment shock. Half of the animals under Punishment Schedule I required punishment shock higher than avoidance shock to meet their assigned suppression criterion. A comparison of all procedures showed that suppression was greater when punishment shock was initially at high intensity.

Peroxidase localization, activity, and isozyme patterns in the developing seedling of vanda (orchidaceae)

Abstract: A B S T R A C T Peroxidase activity in the seedling of I7anda was investigated at var iouls stages of development. Active sites were demonstrated histochemically and soluble proteins and peroxidase isozymes were resolved by disc electrophoresis at progressive stages of growth. Activity, which is highest in the early stages of development and lowest at the stage when maximum differentiation occurs, is confined to the epidermal layer and outer surface of the seedling in early stages of development. It is also present in the vascular tissues of the leaves, root, and parenchymatous region at later stages. Indoleacetic acid raises peroxidase activity when presenit in the growth medium in physiological concentrations. The number of isoperoxidases varies with developmental stage and is lowest in the stage at which leaves and roots are initiated. These observations are discussed in relation to the hypothesis that the peroxidases play a role in morphogenesis as a par t of the indole

Failure to Obtain One-Way Shuttle Avoidance in the Lizard Anolis Sagrei

Abstract: Cuban anoles (Anolis sagrei) were studied in a one-way shuttle procedure with a compound auditory-light stimulus which commenced 5 sec. prior to electric shock onset. None of the 6 lizards learned to avoid, although all animals developed reliable escape responding. Asymptotic performance was quite similar to that obtained in an earlier study which employed a two-way shuttle procedure. The results suggest that auditory and visual stimuli do not become effective conditioned stimuli with lizards when they are paired with an aversive stimulus.

A comparison of the socially influenced behavior of college students and college-age dropouts

Abstract: Patterns of yielding to social influence by educational dropouts and college students contrasted the major theoretical processes of influence. Typical informational social influence was demonstrated by the college students with low yielding on easy and high yielding on difficult tasks. The significant interaction of educational background and task difficulty that was displayed by a factorial analysis of variance design was produced by extremely high yielding of the dropouts on easy tasks and indicated a pattern of behavior interpreted as normative social influence.

Science and Religion: Their Logical Similarity

Abstract: In his “Theology and Falsification” Professor Antony Flew challenges the sophisticated religious believer to state under what conceivable occurrences he would concede that there really is no God Who loves mankind: ‘Just what would have to happen not merely (morally and wrongly) to tempt but also, logically and rightly, to entitle us to say “God does not love us” or even “God does not exist”? I therefore put…the simple central questions, “What would have to occur or to have occurred to constitute for you a disproof of the love of, or of the existence of, God”?’

The mode of action of carbon tetrachloride on Fasciola hepatica.

Abstract: 1 . A biliary fistula was prepared in twelve sheep. 2 . Each animal was given 2 ml. of 14C-carbon tetrachloride (specific activity 15 mc/m-mole) and bile collected at 2, 4, 24 and 48 hr. 3 . Specific activity was measured by liquid scintillation counting before and after each specimen had been heated to 75°C for 10 min to drive off volatile content (carbon tetrachloride). 4 . Only traces of activity were present in the bile and heating did not alter this. 5 . There was no difference in the survival times of adult Fasciola hepatica incubated in Hedon Flieg medium with and without 25% bile from non-medicated sheep, or with carbon tetrachloride in a concentration of 0.03%, but 25% of bile from sheep given 2 ml. of carbon tetrachloride 24 hr before greatly increased lethality in vitro. 6 . The anthelmintic action of carbon tetrachloride on F. hepatica does not result from a direct action due to excretion in bile of unchanged carbon tetrachloride but of an unidentified toxic element not necessarily derived from the drug but which arises as a result of its administration.

Liberals, conservatives, and conformity

Abstract: Patterns of conforming behavior were compared for Ss empirically contrasted as conservatives, moderates, or liberals on a politically based Thurstone-type scale. In a split-plot factorial analysis-of-variance design, liberalism-conservatism of the Ss and political identification of the influence sources were employed as between-Ss variables, while task difficulty operated as a within-Ss variable. The finding of major interest was that conservatives conformed more than moderates who conformed more than liberals. Further analysis revealed that, in general, conservatives were conformen, liberals were independent, and the conformity of moderates was dependent on the nature of the judgmental task.

The effect of deprivation upon fixed ratio responding

Abstract: The effect of food deprivation upon fixed-ratio responding was studied in two pigeons. Post reinforcement pausing and response rate were considered separately. Both birds showed significant decreases in pausing as deprivation increased, but response rate did not show a similarly consistent correlation.

Reproductive Characteristics of the Mexican Woodrat at the Northern Limit of Its Range in Colorado

Abstract: The reproductive biology of the Mexican woodrat (Neotoma mexicana) was studied for 16 months along the Front Range of northern Colorado from February 1966 through May 1967. Adult females bred from March through May and produced two litters annually. The mean litter size for adult females was 3.43 ± 0.35 based on embryo counts, 3.66 ± 0.31 based on corpora lutea, and 3.47 ± 0.39 based on placental scars. Juvenile females born in April and May developed rapidly and produced litters in June or July while still partially or wholly in the gray, juvenile pelage. Young females had an average of 2.44 ± 0.27 embryos and 2.52 ± 0.31 corpora lutea. Some young females born late in the reproductive season, ovulated in September and October, but failed to produce litters. Reproductive failure was apparently due to an absence of fertile males in the population at that time. Peak testicular development occurred in April, 1966 and 1967 (mean weight, 1470.6 ± 257.2 and 1540.2 ± 288.4 milligrams, respectively), and minimal testicular size and activity occurred in November, 1966 (mean weight, 119.6 ± 21.7 milligrams). The gonadal development of juvenile males progressed slowly in 1966 compared to juvenile females. Mean testicular weight and activity remained low through November (mean weight, 61.9 ± 12.5 milligrams), then accelerated rapidly in December (mean weight, 476.8 ±81.3 milligrams), and finally reached full reproductive development during the 1967 breeding season.

Conditioning and extinction of conforming behavior

Abstract: Comparisons were made of the conformity conditioning of four experimental groups: conformers reinforced for conformity, conformers reinforced for nonconformity, independents reinforced for conformity, and independents reinforced for nonconformity. Both conforming and independent Ss were conditioned and extinguished to nonconformity by the reinforcement treatment, but neither was conditioned to greater conformity. It was concluded that further empirical description and analysis of social conformity in conditioning terms may be warranted.