Showing papers by "University of Calgary published in 1975"

Hippocampal Rhythmic Slow Activity and Neocortical Low-Voltage Fast Activity: Relations to Behavior

Abstract: Experimental studies attempting to relate brain electrical activity to behavior have become commonplace in the last 25 years. During this period, there have been many advances in the development of techniques of analysis of slow waves or spike events generated in the brain, but comparable sophistication has not yet been applied to the behavioral side of the brain-behavior problem. Many investigators have been content to refer to the activities of their experimental animals or human subjects in terms that are not descriptive of behavior at all but appear to refer to unseen “inferred processes” instead. Thus various types of brain electrical activity have been said to be related to perception, information processing, attention, motivation, arousal, emotion, learning, memory, and the like. These terms are notoriously difficult to define and therefore impair communication from one researcher to another. Thus one researcher may say that an animal is “attentive” when it stands motionless with head up and eyes open, suggesting that it is “staring at something.” A second researcher may interpret the word attentive” to mean that the animal is actively interacting with the environment by sniffing, biting, or manipulating objects. As the data summarized here will show, details of actual behavior are important in the study of brain and behavior, and merit careful observation and precise description.

Low-sensitivity digital ladder filters

Abstract: A class of low-sensitivity digital ladder filters may be realized in the voltage-current domain by direct analogy with the continuous resistively terminated LC ladder filter The problem of unrealizability that is implied by delay-free loops in the discrete signal flow graph is overcome by using transformations that correspond to LC elements that exhibit finite Cube factors The resultant deterioration in the passband of the transfer function is determined from the Blowstein LC ladder sensitivity theory and is, thereby, shown to be low valued at high sampling frequencies The sensitivity properties of this class of digital ladder filters are directly analogous to the LC prototype because each LC element is replaced by a digital multiplier Consequently, if maximum power transfer is approximately maintained throughout the passband of the LC prototype, then the first-order sensitivity of the corresponding digital transfer function to multiply a coefficient quantization is necessarily low valued

Respiratory and Circulatory Responses to Hypoxia in the Lobster Homarus Americanus

Abstract: Contrary to previous reports, oxygen consumption is maintained over a wide range of external oxygen tensions in the lobster Homarus americanus . In animals acclimated to the experimental conditions this response is mediated by increased branchial pumping, increased effectiveness of oxygen uptake by the gills and an increased contribution by the respiratory pigment to the oxygen delivered to the tissues. Circulatory blood oxygen levels are generally high in lobsters resting in well-aerated water. Mechanisms for detection of hypoxia and possible control mechanisms are discussed.

The Randomized Response Technique: A Test on Drug Use

Abstract: Eight hundred fifty-four high school students' responses were employed to compare drug-use estimates derived from either (a) traditional direct questioning regarding use of six drugs, or (b) a more indirect and more anonymous method of inquiry, the randomized response procedure. Results indicated that (1) the randomized response procedure produced significantly fewer response refusals, and (2) significantly higher drug-use estimates supported the hypothesized greater sensitivity and validity of the randomized response procedure. The results further suggested that previous estimates derived from standard forms of questioning many have underestimated incidence of drug-use.

Randomization Tests for One-Subject Operant Experiments

Abstract: Summary If statistical tests are to be applied to data from one-subject experiments, those experiments, like ordinary multiple-subject experiments, should utilize a type of random sampling or random assignment that provides an appropriate basis for the determination of statistical significance. In one-subject operant experiments it is common to assign blocks of treatment times, rather than individual treatment times, to the treatments. This mode of assignment has made it difficult to justify the application of analysis of variance, time-series analysis, and other parametric procedures in such experiments. On the other hand, randomization tests whose validity for such application is assured can be readily developed. Procedures for developing and applying these randomization tests are given.

The effects of a forest fire on soil microfungi

Abstract: The effects of forest fires on the soil mycotlora were investigated in a Pinus contorta forest in Alberta, where it was found that species of Trichoderma and Penicillium were reduced in the burned plot, whereas Gelasinospora sp occurred only in the burned plot: Cylindrocarpon destructans appeared not to be affected by fire. The response of fungi to aqueous extracts of burned and unburned litter, measured as linear growth on agar, showed that, of the isolates tested, all but C. destructans were inhibited by the burned litter extract; C. destructans grew better on the burned litter extract. An examination of spore germination rates and growth in liquid culture showed that Trichoderma polysporum and Penicillium janthinellum were both inhibited by burned litter extracts whereas C. destructans was not. Gelasinospora sp did not grow in liquid culture, nor did it produce spores after being kept in culture for some time. It was concluded that species of Trichoderma and Penicillium were killed by the heat of the fire, and subsequently unable to rccolonize the upper layers of the soil, due to an inhibition of spore germination and growth by the chemical products of burning. C. destructans on the other hand may have been able to recolonize quickly as it appeared to be stimulated in its linear growth rate by the chemical products of burning, and its spore germination rate was only marginally lowered. The occurrence of Gelasinospora sp following fire is possibly explained by its extremely rapid growth rate, and the possibility of its ascospores being more able to withstand high temperatures in the soil. In the light of recent reports, indicating that some species of Trichoderma and Penicillium are actively antagonistic to other fungi, it is suggested that their absence after fire, in the area studied, may permit a high inoculum of C. destructans to develop in the soil, which could possibly result in a high incidence of disease in developing pine seedlings

Chromatin-associated RNA content of heterochromatin and euchromatin.

Abstract: Chromatin from TLT hepatoma cells, mouse liver cells, and mouse brain cells was fractionated by differential centrifugation into a pellet, enriched with heterochromatin, and a supernatant, enriched with euchromatin. The pellet was found to contain more than twice as much of a particular species of chromatin-associated RNA per milligram chromatin DNA as did the supernatant. This chromatin-associated RNA was also found to be associated with the transcriptionally inactive chromatin of mature avian erythrocytes. Bull sperm, whose genome is known to be completely inactive, was used as the source in the preparation of sperm heads. Bull sperm head RNA appeared to consist of a single, low molecular weight species which migrated on polyacrylamide gels at a rate just slightly slower than the aforementioned chromatin-associated RNA. The results are interpreted as indicating that this chromatin-associated RNA is more prevalently associated with the heterochromatic fraction of chromatin. It is postulated that this chromatin-associated RNA might constitute a structural component of heterochromatin.

In utero development and maturation of the retina of a non-primate mammal: a light and electron microscopic study of the guinea pig.

Abstract: A light and electron microscopic examination of retinogenesis in the fetal guinea pig has revealed an early development of synapses and photoreceptor cells Differentiation of the neural retina begins around day 23 of gestation By 34 days the retina reaches its maximum thickness It differentiates an inner plexiform layer in which vesicle-containing processes and primitive synapses are evident Synaptic ribbons are found in processes of this layer by 43–45 days of gestation An outer plexiform layer develops within the neuroblast layer at 40 days of gestation; from its first appearance the outer plexiform layer contains synapses complete with synaptic ribbons Receptor terminals of the α, paranuclear and β type are present well before birth Photoreceptor cells form inner segments by 40 days; the formation of outer segments is indicated by 45 days but not widespread until 49 days The retina appears mature by day 51–57 It is clear that the primate is not unique in the early differentiation of its retinal synapses relative to the time of maturation of its photoreceptor cells The potential functional capacities of precocious retinae, and the mechanisms of synapse development are discussed

Enzyme to break down lettuce endosperm cell wall during gibberellin-and light-induced germination

Abstract: THE physiology of lettuce seed germination has been a subject of extensive study, but very little is known of the fundamental biochemical events which occur during germination. Here we report that the endosperm cell wall is largely composed of a mannose polymer (that is, a man-nan); and that germinating seeds produce an enzyme capable of its breakdown.

Differential fluorescent staining of human chromosomes with daunomycin and adriamycin--the d-bands.

Abstract: Human chromosome preparations were treated with a group of anthracycline antibiotics. Well-defined, orange-red fluorescent bands were observed on chromosomes after the slide was stained with daunomycin and adriamycin but not with nogalamycin. The characteristic differential bands appeared to be similar to the banding patterns obtained by the quinacrine techniques. Interaction of these antibiotics with DNA could provide information on the general mechanism of fluorescent banding. Further, these bands (D-bands) appeared to be more stable than the Q-bands and may have some usefulness for routine clinical cytogenetic analysis.

Some Bits and Pieces

Abstract: These are some bits and pieces on the distinction between count nouns and mass nouns in an attempt to investigate the semantic and/or ontological significance of that distinction.1 Count nouns are nouns like ‘label’, ‘fable’ and ‘table’, and mass nouns are nouns like ‘milk’ and ‘honey’ and ‘silk’ and ‘money’. My question is whether count nouns correspond to counting things and mass nouns to amassing stuff and also whether there is a corresponding ontological difference in what we talk about.

Inequities in the Organizational Experiences of Women and Men

Abstract: Women face consistent disadvantages in their experiences in organizations, as evidenced by inequities in interpersonal attractiveness, social isolation, job satisfaction, and work strain. The question raised is whether these disadvantages are due simply to differences in access to key organizational resources (expertise, professional rank, and authority), or to the advantages men have in real izing their vested interests in the face of competition from women. The vested interest interpretation receives strong inferential support, while the interpretation based on differential access to resources receives little confirmation. The concept of compartmentalized rationality is developed in.exploring the implications of the findings. Differences in the experiences of women and men in some sorts of social activity have been much studied and, as a result, are generally familiar in the discipline. Yet, in organizational research, direct comparisons between men and women are rare. The reasons for this vary. Some have speculated that women react to work in organizations in a fundamentally different way than men do (Etzioni), and this has occasionally caused women to be excluded from an analysis altogether (Shepard). Others have studied women at work but have not explored the importance of sex, per se, in determining behavior. (For a comment on this, see Acker and van Houten.) Whatever the reason for the oversight, given our ignorance on the subject there is little doubt that the interaction patterns and exchanges of rewards that develop in organizations would stand out more clearly if sexual differentiation were taken into account. With this in mind, we have investigated patterns of sexual differentiation in five small, highly professionalized organizations. Information from these organizations was used previously to explore the social-psychological implications of Weber's model of bureaucracy (Miller and Fry), but this is the first time that the possibility of sexual inequities has been directly investigated. The research proceeded in two stages. First, the differences between men and women in three areas of organizational activity were determined: 1. differences in access to organizational networks of interaction were examined, using sociometric measures of interpersonal attractiveness (specifically, friendship, perceived influence, professional respect and or*This research was sponsored in part by NIMH grant no. 23274-01 Al and by the Social Sciences Research Institute of the University of Southern California. We are grateful to Steven Bloch for his assistance in the analysis of the data, and to our colleagues, too numerous to Iist, for their perceptive comments on early versions of the paper.

Effect of aeration on the flood-induced formation of adventitious roots and other changes in sunflower (Helianthus annuus L.)

Abstract: The effects of flooding, flooding with aeration, and no flooding of the root system on shoot growth was studied in sunflower plants. The responses of shoots appear to be brought about by: (1) The anaerobic condition of the roots which causes stem dwarfing, chlorosis, and petiolar epinasty. (2) The presence of water in excess of field capacity (but not anoxia) around the roots which results in an increase in stem hypertrophy and the formation and growth of adventitious roots.