SURFACE TENSION OF COMPOSITIONS IN THE SYSTEMS PbO-B2O3 AND PbO-SiO2*

The surface tension of a series of compositions ranging from 0 to 100% PbO in the system PbO-B₂O₃ and of compositions ranging from 0 to 35% SiO₂ in the system PbO-SiO₂, was measured by a modification of the anchor ring method. The volatility and changes in composition of members of each system on heating were found to be related to the surface tension and its change with composition. Some correlation between the temperature coefficient of surface tension and expansivity was noted.     

The toxic effects of trinitrotoluene (TNT) and its primary degradation products on two species of algae and the fathead minnow

The effects of alpha trinitrotoluene (alpha TNT) and its primary degradation product (TNTcc), commonly referred to as “pink water”, were determined on members of two trophic levels. The growth responses of the algae Selenastrum capricornutum and Microcystis aeruginosa were examined through static bioassays. Death and behavioral responses of the fathead minnow (Pimephales promelas) were determined using a proportional diluter. Alpha TNT and TNTcc were both more toxic to the fathead minnow than to either species of alga. Five and 15 mg l⁻¹ alpha TNT inhibited S. capricornutum and M. aeruginosa growth, respectively. TNTcc inhibited S. capricornutum growth at concentrations above 9 mg l⁻¹; it was lethal to M. aeruginosa at 50 mg l⁻¹, but stimulated growth at lower concentrations. The 96-h lc₅₀ values based on the death response of the fathead minnow to alpha TNT and TNTcc were 2.58 and 1.60 mg l⁻¹, respectively. The 96-h ec₅₀ values based on the behavioral responses were 0.46 and 0.64 mg l⁻¹, respectively. There was no response to concentrations of 0.05 mg l⁻¹ alpha TNT and 0.07 mg l⁻¹ TNTcc.     

SURFACE TENSIONS OF SOME OPTICAL GLASSES*

The surface tension of a number of optical glasses made at the National Bureau of Standards was measured by a modification of the anchor ring method. The values for the flint glasses at 1300 °6, were in the range 210 to 230 dynes per cm., the barium crowns ranged from 260 to 310, while the other types of glasses had intermediate values. Most of the glasses had positive temperature coefficients of surface tension. The surface-tension values increased with the increasing periods of time at which the glasses were maintained at high temperatures immediately prior to measurement. Positive rank correlation coefficients of statistical significance were found between seed quality of optical glasses and such factors as surface tension, pot attack, and amount of gas liberated during the melting process.     

Sensory capacities of marine mammals.

Examines the sensory capacities of aquatic and amphibious marine mammals and compares them with those of terrestrial primates. Auditory masking studies indicate comparable inner-ear functioning for aquatic, amphibious, and terrestrial mammals. Detection data from aquatic audiograms depict acute sensitivity to low intensities with extensive frequency ranges. Relative intensity sensitivity indicates that amphibious mammals have an aerial loss comparable to the aquatic loss for humans. Aquatic mammals have discrimination capacities for frequency, intensity, duration, and localization approximating those of humans. However, the differential sensitivity of amphibious mammals, though comparable to many terrestrial forms, is inferior to that of humans and aquatic forms. Visual detection data are almost nonexistent, and data on discrimination indicate relatively well-developed spatial acuity. Finally, the chemoreceptive modalities of olfaction and taste have degenerated considerably. (148 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Productivity of women physicians

Personal interview data obtained from 87 randomly selected women physicians in metropolitan Detroit indicates that productivity of women physicians has increased over that shown in previous studies. Eighty-four percent were engaged in medical work at the time of survey, 90% full-time. Only 7% were not working for reasons related to being a woman. Fifty-nine percent had worked continuously full-time since medical school graduation. Nearly half do not plan to retire from medical work. Fifty-eight percent are in private practice and 51% in primary care specialities; 54% are board certified. Direct patient care was listed as their main task by 86% of the women. Sixty-seven percent are married (43% to physicians). Although the 87 women physicians have responsibilities for households containing a total of nearly 300 people, almost one third of whom are children under 18 years old, their productivity is high.     

Replication and comments: "An experimental reunion of psychoanalytic theory with perceptual vigilance and defense."

"The results of an initial attempt to replicate the results of Blum's experiment (see 28: 6928) indicated that stimulus similarity was an important determinant of errors of localization in the test of the perceptual defense hypothesis. A second experiment was designed to test the defense hypothesis under the specified conditions and at the same time yield information concerning the role of stimulus similarity on errors of recognition in the defense series. The results indicated similarity among the experimental and control stimuli was the primary determinant of the frequency of correct response… . Evidence was presented which tentatively suggests that systematic errors of localization might be due to an increased generalization gradient associated with anxiety arousal." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facebook as a toolkit: A uses and gratification approach to unbundling feature use

Research on social network sites (SNSs) typically employ measures that treat SNS use as homogenous although the user-base, user practices, and feature sets of these tools are increasingly diverse. Using a uses and gratifications approach, we address this problem by reconceptualizing SNSs as collections of features. Survey data collected from undergraduate students at a large Midwestern university (n = 267) revealed that users’ motivations for using Facebook predict their use of different features, such as status updates and Wall posts, but features that share similar capabilities do not necessarily share underlying motivations for use. When these results are contrasted against models employing a more unidimensional measure of Facebook use, we find differences between motivations for both general Facebook use and use of specific features of the site. This suggests that unidimensional measures of SNS use obfuscate motivations for using specific features. Theoretical and methodological implications of these findings and this approach are discussed.     

The influence of stress on the perception of incongruity.

The results of two experiments "support the hypothesis that psychological stress results in (a) premature closure and (b) a tendency to adhere to expectancies (prerecognition hypothesis) in ambiguous task situations. From these two sets of data it is inferred that stress or anxiety results in cognitive and perceptual processes that tend to preserve a familiar perceptual and behavioral field for the individual." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On Cognitive Development.

Comments on "The Course of Cognitive Development," by J. S. Bruner (see record 1964-06801-001). Certainly many issues to developmental psychology emerge from consideration of Bruner's genetic approach to cognitive growth. This comment seeks to clarify certain basic differences in theory and methodology between the Harvard and Genevan cognitive growth projects that have the common purpose of investigating the underlying processes which control the transition from one mode of thinking to another. Theoretical differences centering on the nature of developmental changes resulted in differences in the kind of transition studied as well as in the conclusions regarding the processes underlying the cognitive learning. The current authors share Bruner's general theoretical concept of development as an integrative process and agree that information-processing techniques are of great importance in the study of cognitive development. However, it seems necessary to emphasize that information-processing techniques have several aspects of which Bruner and his co-workers have studied only some. Information-processing techniques seem to consist, on the one hand, of selection, of storage, and of retrieval of relevant cues. On the other hand, these techniques imply transformation of information and its coordination. The latter is the fundamental concern of the Genevan project. (PsycINFO Database Record (c) 2010 APA, all rights reserved)