Showing papers by "San Diego State University published in 1976"

The Developmental Progression of Manipulative Play in the First Two Years.

Abstract: FENSON, LARHY; KACAN, JEROME; KEAHSLEY, RICHARD B.; and ZELAZO, PHILIP R. The Developmental Progression of Manipulative Play in the First Two Years. CHILD DEVELOPMENT, 1976, 47, 232-236. Age differences in play were examined cross-sectionally at 7, 9, 13, and 20 months. Play at 7 months veas characterized by close visual and tactual examination of single objects, accompanied by mouthing. 13-month-olds showed more interest in physical and functional relations among dimensions of the toys, a trend that was discernible at 9 months. The emergence, during the last quarter of the first year, of the ability to relate 2 objects signals an important advance in cognitive functioning. Relational play precedes symbolic play developmentally.

Irradiance reduction: Effects on standing crops of the eelgrass Zostera marina in a coastal lagoon

Abstract: Abundance of the eelgrass Zostera marina L. was studied in a coastal lagoon in southern California (USA), and was found to correlate with the level of irradiance at depths greater than 0.5 m below tidal datum. Results of controlled field experiments, using canopies to reduce downwelling illuminance by 63%, confirmed that turion density is a function of the irradiance the plants receive. By Day 18 of the experiment, turion density in the shaded experimental areas had decreased compared to the density of adjacent unshaded controls. Turion densities were continually lower throughout the 9-month study in the experimental areas, which at the end of the study had a turion density only 5% that of the control areas. Flowering in the experimental areas was also inhibited by shading. The biological implications of these findings are discussed with respect to seasonal changes in incident solar radiation, water transparency, and changes in water quality due to man's increased intervention in the natural processes of coastal lagoons.

Transition probabilities in the spectra of Ne i, Ar i, and Kr i

Abstract: Transition probabilities have been computed for the following arrays: Ne i 3p–3d, Ar i 5s–4p, 4p– 4s, 5p–4s, 3d–5p, 4p–3d, and Kr i 5s–5p. Intermediate-coupling theory, including an effective operator, has been used. An absolute scale is obtained by use of the Coulomb approximation. The eigenvectors obtained in this manner give a better fit to the observed energies and Lande g values than eigenvectors obtained without the effective operator. There is also a significant improvement of agreement of the calculated transition probabilities to the few experimental values for these arrays.

Television Violence and Viewer Aggression: A Reexamination of the Evidence

Abstract: Studies of the effects of fantasy violent content in television on aggressive behavior are reviewed and used to assess three positions: (a) an activation view that watching televised fantasy violence causes aggressive behavior, (b) a catharsis view that aggression in some groups may be decreased following the observation of such violence, and (c) a null view that such violence on television has not been demonstrated to have significant effects on aggressive behavior. Studies are discussed with regard to their representativeness in sampling and design. In contrast to earlier reviews which have advocated the activation position, the evidence is here interpreted as supporting the null view.

Enhancement of CO2 Uptake in Avena Coleoptiles by Fusicoccin

Abstract: When Avena coleoptile segments are immersed in a solution containing H14CO3−, the appearance of label in the tissue is stimulated approximately 3-fold by fusicoccin application. This effect is rapid (1-2 minutes lag time), dependent upon respiratory energy, inhibited by carbonyl cyanide m-chlorophenylhydrazone, but not appreciably altered by cycloheximide treatment. A large percentage of the cellular radioactivity is found in the form of malate. Preliminary experiments indicate that CO2, as opposed to HCO3−, is the favored species of “CO2” taken up by the segments. These results are consistent with the notion that CO2, presumably by virtue of its fixation and conversion to malic acid, participates in the early events associated with fusicoccin-enhanced acidification of the cell wall region leading to the stimulation of cell extension growth.

Influence of physical activity on stability of somatotypes in boys.

Abstract: The purpose of this study is to examine the stability of somato-types of boys with different activity levels followed longitudinally for eight years. Thirty-nine boys aged 11 were somatotyped annually (until 18 years) using the Heath-Carter anthropometric rating method. Three sub-groups were formed according to their levels of systematic physical activity designated High, Moderate, and Low Activity. There were no differences in somatochart distributions of the Total Group, but there were considerable individual changes which cancelled each other in group comparisons. All boys changed their somatotype ratings at least once and 67% changed in component dominance. The inter-age correlations for the components were generally of poor prediction value, and the somatotype migratory distances showed considerable variation. The Total Group means differed on three components and this was attributed to differences within the Moderate Activity Group, the only sub-group to differ. It was concluded that changes occur in somatotypes of adolescent boys, but the influence of physical activity on the changes is inconclusive.

Liquid Jet Pumped by Rising Gas Bubbles

Abstract: From observations of a stream of gas bubbles rising through a liquid, a two-phase mathematical model is proposed for calculating the induced turbulent vertical liquid flow. The bubbles provide a large buoyancy force and the associated drag on the liquid moves the liquid upward. The liquid pumped upward consists of the bubble wakes and the liquid brought into the jet region by turbulent entrainment. The expansion of the gas bubbles as they arise through the liquid is taken into account. The continuity and momentum equations are solved numerically for an axisymmetric air jet submerged in water. Water pumping rates are obtained as a function of air flow rate and depth of submergence. Comparisons are made with limited experimental information in the literature.

Computer modeling of erodible flood channels and deltas

Abstract: The existing computer program for water-surface computation and delineation of the flood limit has been extended to include the effect of channel deformation during a flood. In the new program, the unsteady flow is approximated by successive temporal steady conditions; the change in channel boundary is corrected at each time step. This computer program has been applied to obtain the progressive changes of the channel boundary and water-surface profile during a flood as a result of erosion and sedimentation. By imposing an additional condition for the delta, another computer program has also been developed to compute the progressive growth of the delta of the river mouth and the variation of the delta stream pattern. /ASCE/

Community medicine. Informed consent. Emotional responses of patients.

Abstract: A study was made of the effects on patients of detailed written information about a forthcoming hysterectomy. Results showed that knowledge of risks and possible complications did not increase preoperative anxiety levels or deter patients from undergoing surgery and was possibly beneficial in that anxiety levels after surgery were lower in experimental subjects than in controls.

Differential seed predation on two species of Arctostaphylos (Ericaceae).

Abstract: The fire-prone California chaparral contains two sympatric species of shrubs: Arctostaphylos glauca and A. glandulosa. A previous study showed that in a stand where both species had similar amounts of coverage, A. glauca had fewer seeds in the soil. We attempt to answer the questions: 1) Could ground-foraging seed predators produce the lower population of A. glauca seeds in the soil? 2) Do predators select fruits randomly with respect to fruit size? 3) Do the fruits of the two species differ in the proportions of fruit components (i.e. seeds, endocarp, mesocarp, and exocarp) in ways that could be important to seed predators? Predation was measured on artificial caches of fruits, for 17 weeks. Selection by predators was examined by comparing weights of fruits recovered from soil samples with newlymatured fruits on the shrubs. Fruits components were characterized by dividing fruits into 3 fractions and weighing. More fruits of A. glauca were removed from the caches. Fruits of both species recovered from the soil were lighter than those on the shrubs. The weights of seeds, stony and fleshy fruit layers were all larger in A. glauca. Within fruits of A. glandulosa, the weights of the three components, various combinations, and ratios were all significantly correlated, while in A. glauca no other component, combination of components, or ratio examined was significantly correlated with the weights of the seeds.

Pre-eocene Paleosol South of Tijuana, Baja California, Mexico

Abstract: In the Rancho Delicias area south of Tijuana, Baja California, well preserved remnants of an ancient weathering profile are developed on mid-Cretaceous granodioritic rocks. The paleosol is buried beneath Middle Eocene marine sedimentary rocks of the Delicias Formation. It has a 16 m thick C horizon characterized by grus decomposed to varying degrees. The A horizon is a severely leached oxisol that exceeds 13 m thickness and consists of approximately [2]/[3] kaolinite and [1]/[3] residual quartz gains with minor iron oxide concretions near the top. Thick latosolic soil profiles dominated by kaolinite form today only in near equatorial areas which have around 25° C average annual temperature and greater than 1,200 mm yearly rainfall. The Late Cretaceous to Early Eocene climate of th San Diego-Tijuana region was probably like that of the hot and humid areas found within 20 to 30° of the modern equator, and very unlike the present temperate, arid climate.

Phagocytosis of chloroplasts in Placida dendritica (Gastropoda: Sacoglossa)

Abstract: Phagocytosis of algal chloroplasts by digestive gland cells in the sacoglossan opisthobranch Placida dendritica is described. It is suggested that engulfment of chloroplasts is accomplished by veils of cytoplasm which are derived from elongating microvilli.

Specific attentional effects reflected in the cardiac orienting response

Abstract: Twenty-four undergraduates listened to 60-sec strings of synthetic speech syllables containing a syllable change in the middle of the string. No response was required but half of the subjects were instructed to “listen for a change.” Instructions did not affect cardiac orienting to onsets or offsets of the strings but did determine whether or not orienting occurred to a change that all subjects reported hearing. The findings imply that a failure of nonverbal subjects to orient to stimulus change cannot be accepted as evidence that the change is not discriminated.

Optimal Investment Scheduling with Price-Sensitive Dynamic Demand

Abstract: A model is developed that integrates capital investment decisions with output and pricing decisions for a situation of growing demand. Conditions are derived for the model that permit application of a general approach for determining the optimal sequence and timing of investments in a continuous-time framework. The behavior of optimal pricing and output decisions is characterized analytically. Specific results are given for a quadratic cost and revenue case, and an example illustrates the form of a solution. Possible extensions of the model are also discussed.

Aspects of Attention, Orientation, and Status Hierarchy in Mandrills (Mandrillus Sphinx) and Gelada Baboons (Theropithecus Gelada)

Abstract: Social visual attention, body orientation, and the status hierarchy were studied in groups of baboons, Mahdrillus sphinx and Theropithecus gelada. In the gelada group, social attention of the dominant male was found to be directed more to his group than was the case in the mandrill group. This was correlated with a greater amount of mutual visual attention between the dominant male and his harem in geladas, relative to the mandrills. A general discussion of the Importance of vigilance for external danger in group living primates was presented, with particular reference to the role of the dominant male. Secondary referents (statistically significant peaks of social attention) were found to occur in the lower levels of the status hierarchy in both groups. This was related to a current theory of primate aggression. Body orientation was related to avoidance of presenting a potentially threatening posture in mandrills and to sexual advertisement in geladas.

Fish-bone oil: Percent total body lipid and carbon-14 uptake following feeding of 1-14C-palmitic acid

Abstract: Bones contain the majority of body lipid in some marine fish. In the sheepshead wrasse Pimelometopon pulchrum and the sablefish Anoplopoma fimbria, the bone lipid comprised 79 to 93% and 52 to 82% of the total body lipid, respectively. The senorita Oxyjulus california, another species of wrasse, has only 14% of its body lipid in bone. To determine whether dietary lipid is deposited quickly in the bone lipid, three species of fish were fed 1-14C-palmitic acid. Radioactivity appeared in the bone lipid as soon as 12 h after feeding, with the species rich in bone lipid incorporating the highest activity relative to the flesh. Roughly 80% of the radioactivity recovered in A. fimbria bone lipid was found in triglyceride. Radioactivity was equally distributed between phospholipid and triglyceride in P. pulchrum bone lipids. The results suggest that in some marine fish the bones contain the majority of the organism's reserve energy.

Correlation between two measures of self-esteem and drug use in a college sample.

Abstract: The relationship between drug and alcohol use and self-esteem was investigated using students living in a co-ed dormitory. A questionnaire was distributed containing four sections including demographic information, the Coopersmith Self-esteem Inventory (1967), an A Priori Identity Crisis scale, and a frequency of drug/alcohol use scale. 66% of the questionnaires were returned, yielding a sample of 171 males and 219 females. Heavy use of alcohol was related to low self-esteem. No relationship, however, was found between drug use and self-esteem. The relationship between drug and alcohol use and psychopathology is discussed as being a continuum.

Sales Force Participation in Quota Setting and Sales Forecasting: Sales Managers Report on the Extent and Accuracy of Forecasting by Their Sales Forces

Abstract: A outside sales force is potentially one of its best sources of market and sales forecasting information, especially under unique economic conditions which make historical data unreliable. Yet many sales managers do not use inputs from their salespeople for forecasting sales or establishing performance goals. Those who do solicit such information may have to modify these inputs up or down depending on such factors as the abilities of the men or women comprising the sales force, their knowledge of company plans, and potential deliberate distortion of data because the salespeople feel that their estimates will be used later in setting their quotas or in determining their level of pay. Thus, asking a sales force for future sales estimates and using these inputs in any fashion requires a degree of caution and a concern for just how to interpret that information. This article reports the results of a study designed to investigate the extent of sales force participation in sales forecasting and quota setting in different kinds and sizes of companies. It also examines the experiences of sales managers in interpreting and using such data.