Showing papers by "University of Sydney published in 1969"

On cross‐cultural comparability

Abstract: La necessite se fait sentir, pour les psychologizes qui travaillent dans une perspective interculturelle, d'expliciter leurs methodes et de parvenir a un certain consensus qui permette de juger et de comparer les resultats. L'auteur propose ici un cadre de travail methodologique pour la recherche interculturelle, qui s'inspire des discussions passees de certains anthropologues. Trois conditions s'averent necessaires si l'on veut donner quelque validite aux comparaisons interculturelles des comportements: 1° Il faut d'abord demontrer qu'il y a equivalence fonctionnelle des comportements dans l'une et l'autre des cultures considerees; c'est-a-dire que seul, un comportement qui cst une reponse a un probleme identique peut ětre compare. 2° On peut, a titre d'essai, partir d'une conception du comportement observe qui est independante des cultures considerees (generalite hypothetique) a condition que ce soit seulement comme point de depart et que ce comportement soit ensuite concu dans les termes měmes...

Crab Nebula Pulsar NP 0532

Abstract: BECAUSE of the conjecture that pulsars are neutron stars, which are possibly produced in supernova events, the possible association of pulsars with supernova remnants is of great interest. Staelin and Reifenstein recently reported1 the discovery of two pulsed radio sources near the Crab nebula, which is the remnant of the supernova observed by the Chinese in AD 1054. Pulses from both sources were described as very sporadic, and no periodic phenomena were evident.

Congenital defects in guinea pigs: Prenatal retardation of brain growth of guinea pigs following hyperthermia during gestation

Abstract: Hyperthermia was induced in pregnant guinea pigs for 1 hour on 2, 4, or 8 consecutive days between days 4 and 67 of gestation. Mean newborn brainweight was reduced substantially and incidence of micrencephaly increased following hyperthermia on 4 or 8 successive days during days 15 to 32, and apparently to a lesser degree following exposure on days 39 to 46, and 53 to 60 of gestation. Maternal hyperthermia at other than these periods was associated with little or no reduction in mean brainweight or increase in incidence of micrencephaly. Following hyperthermia on 2 successive days during days 14 to 31 of gestation the incidence of micrencephaly was increased and mean brainweight decreased in offspring from females heat stressed on days 16–17, 20–21, 22–23, and 24–25. The effects of hyperthermia on brain growth were most marked on days 20–21 or 22–23. Following 1 hour of maternal heat stress on day 21 of gestation, brainweight of newborn animals was reduced if maternal body temperature was elevated more than 2.5°C above normal. For each 1°C elevation in body temperature above this level brainweight was reduced by approximately 8.4% compared with control values.

Multiple projection of the visual field to the medial portion of the dorsal lateral geniculate nucleus and the adjacent nuclei of the thalamus of the cat

Abstract: The organization in the cat of the projection of the visual field onto the medial part of the central half of dorsal lateral geniculate nucleus (LGNd), the medial interlaminar nucleus (MIN) and the posterior nucleus of the thalamus (PN) has been studied by systematically plotting the receptive fields of single units isolated in the nuclei by tungsten microelectrodes. Using a grid of verticals (azimuth) and horizontals (elevation), projection maps were prepared by locating the recording sites of the units in serial histological sections. We have plotted three separate but related topographical projections of the visual field, one in each nucleus. Particular attention was paid to the projection of the visual axis in the LGNd. With the possible exception of the upper periphery, the whole of the visual field is represented in the MIN, the topographical organization with respect to azimuths being the mirror-image of that in the LGNd. There were very few binocularly activated units in the MIN and no evidence was found of a laminar segregation of crossed and uncrossed optic tract terminals. The topographical projection onto the PN resembled that in the MIN except that the upper visual field was even more restricted and the organization of azimuth values was again reversed such that the central visual field projected inferomedially and the peripheral field dorsolaterally. In all three nuclei a naso-temporal overlap was found with receptive fields located across the midline in the ipsilateral hemifield for about 2° in the case of LGNd units and 6° or more in the case of the MIN and PN. Some observations are made on visually active units in the lateral posterior nucleus of the thalamus and the pulvinar, many responding binocularly.

Settlement of Single Compressible Pile

Abstract: The settlement behavior of a single compressible floating pile is analyzed and influence factors are presented for the settlement for a wide range of values of length-to-diameter ratio L/d and pile stiffness factor K , a measure of the relative compressibility of the pile and, for a solid pile, the ratio of the Young's moduli of the pile and the soil. The value of K markedly affects the settlement and the shear stress distribution along the pile and has a considerable influence on the load-settlement behavior of a pile loaded to failure in a saturated clay under undrained conditions. However, the ratio of the immediate to the total final settlement is only slightly affected by K while the settlement reduction due to an enlarged pile base is almost independent of K . The value of K at which the pile behaves as an incompressible pile (for which K = [infinity]) increases as L/d increases. Comparisons between the theoretical behavior of a pile and that reported from field measurements of piles in clay show encouraging agreement.

Inhibition in the medial geniculate body of the cat.

Abstract: 1. Inhibitory activity in the cat medial geniculate body (MG) was examined by stimulating electrically and acoustically the input and output of the MG. 2. A longer and more profound depression of excitability occurs following a click-evoked potential in the MG than in the inferior colliculus (IC) in both anesthetized and unanesthetized states. Recovery is cyclic in the barbiturate MG preparation. 3. Electrical stimulation of the brachium of the inferior colliculus (BIG) evokes a field potential in the MG consisting of clearly distinguishable presynaptic and postsynaptic components. The presynaptic component recovers rapidly, while the postsynaptic component requires 100–200 msec for full recovery. This depression of excitability is localized within the MG since cortical ablation does not alter its occurrence. 4. Stimulation of the BIC mimics the effects of click stimulation on single units. Excitatory, inhibitory and reverberatory responses are evoked by the BIC shock. Suppression of single unit activity correlates with the depression of excitability following a BIC-evoked field response. 5. Cortical stimulation can evoke antidromic and trans-synaptic unit responses in the MG, as well as causing a variety of inhibitory effects and reverberation. In view of the fact that cortical ablation does not impair the recording of these responses to afferent stimuli, it is suggested that the cortical-evoked responses are at least partly mediated by antidromic conduction to MG. 6. Evidence is presented that inhibitory effects of both afferent and cortical stimulation are due to active inhibition of MG unit activity. Speculations are made as to the mechanisms producing inhibition and reverberation in the MG.

Amphiphile Nature of κ-Casein as the Basis for its Micelle Stabilizing Property

Abstract: The N-terminal two-thirds of the milk micelle stabilizer κ-casein are hydrophobic and the C-terminal third is hydrophilic; the protein is an amphiphile. The two regions may function respectively to anchor the κ-casein molecule to the hydrophobic calcium αs-β-caseinate core and to provide a solvated coat which stabilizes the micelles against aggregation.

The Poet Cn. Naevius, P. Cornelius Scipio and Q. Caecilius Metellus

Abstract: It was many years after the last premiere of a Terentian comedy that the first attempts to write the history of Latin poetry appeared. Scholars had available little documentary material regarding the poets of the late third and early second centuries except the texts of poems, dates of performance of so-called carmina in priestly archives and of so-called fabulae in magisterial archives, and inscriptions on tombstones. These poets were without exception slaves or non-Roman clients of the great aristocratic families and their persons were not well regarded in the community at large. Neither the attitude to poetry of Roman society nor the example of Greek historiography permitted the chroniclers of Roman public life to take account of them. The poets who wrote for the theatre of fifth-century Athens came for the most part from well-regarded citizen families and practised an honoured craft. Although those of them who wrote comedies had much to say about Athenian public life and although their prejudices tended to correspond with his own the great Thucydides had ignored them. Their first biographers found themselves as badly off for contemporary documentary material as Roman writers were to be and yet by the exercise of judgement and fancy in interpreting the extant texts succeeded in constructing extensive narratives. The Roman writers took over Greek methods here as in other areas.

Genetic Variability in Root Development in Relation to Drought Tolerance in Spring Wheats

Abstract: Fifteen Australian and exotic wheat varieties revealed genotypic differences in their patterns of root development and drought tolerance. Earliness in plant maturity, which accounted for 40 to go per cent of the observed variation in drought tolerance, appeared to be by far the most important characteristic of tolerant genotypes, but there nevertheless appeared to be a measurable relationship between some parameters of root development, water use efficiency and drought tolerance. The impact of study of this kind on the problem of breeding for drought tolerance is briefly discussed.

The regulation of pea-seed phosphofructokinase by phosphoenolpyruvate

Abstract: 1. Pea-seed phosphofructokinase was purified 27-fold by a combination of fractionation with ethanol and ammonium sulphate. Under the conditions of assay, the enzyme was strongly inhibited by phosphoenolpyruvate. This inhibition was reversed by increasing the concentration of fructose 6-phosphate or magnesium chloride, or by lowering the ATP concentration. 2. Citrate, ADP and AMP inhibited phosphofructokinase and increased the sensitivity to phosphoenolpyruvate inhibition. Sulphate and inorganic phosphate stimulated the enzyme activity and decreased the sensitivity to phosphoenolpyruvate. 3. In the presence of inorganic phosphate and low concentrations of ATP, inhibition by phosphoenolpyruvate ceased and phosphoenolpyruvate became stimulatory. 4. The possible significance of these results in the control of plant carbohydrate metabolism is discussed.

Compressibility‐Pressure Gradient and the Constitution of the Earth's Outer Core

Abstract: Summary Re-interpretation of seismic data used by Birch in respect of the Earth’s outer core indicates that his finite-strain theory, while serviceable to a useful first approximation, is probably not adequate for drawing fine conclusions on the variation of the incompressibility with pressure in the core. On currently available seismic data, there is a strong suggestion of mild inhomogeneity inside the outermost 700 km of the core. The whole region from 2700 to 3600 km depth seems to be slightly abnormal, with a faint suggestion of continuous change of phase in the outer part of the core. The conclusions are sensitive to the values in determinations of seismic P velocity gradients in the outer core, and it is desirable that some renewed attention be given to estimating the precision of the determinations.

Fatty acid desaturase systems of hen liver and their inhibition by cyclopropene fatty acids

Abstract: Hen liver preparations which desaturate stearic acid at the 9,10 position to form oleic acid have been found to desaturate other saturated fatty acids of carbon chain length from 12 to 20 and 22. The 9,10-monoenoic fatty acid of the same chain length as the substrate fatty acid is the major product formed. Minor amounts of the 10,11- and 11, 12-monoenoic acids are also formed. Maximum desaturation occurred with the C14 fatty acid substrate and with the fatty acids C17 and C18, suggesting the presence of at least two desaturating systems. The cyclopropene fatty acids, sterculic and malvalic acids, inhibited the desaturation of all thefatty acids at the 9,10 position but desaturation at the 10,11 and 11, 12 positions was affected only slightly. The effect is not due to inhibition of the primary activating enzyme, the long chain acyl CoA synthetase. Sterculic acid is a more effective inhibitor than either malvalic acid or sterculyl alcohol, probably because these cyclopropene compounds do not block the desaturating site of the enzyme as completely as sterculic acid.

Upper Bound to Change in Incompressibility at the Earth's Mantle-Core Boundary

Abstract: Summary A series of Earth models has been constructed in which the excess Ak of the incompressibility at the top of the Earth’s core over the value k at the bottom of the mantle has been given the assigned values 0, 0.05, 0.1, . . ., x 10” dyn/cm2. The calculations indicate that unless the assumed seismic velocities and density gradients are more seriously in error than expected, Ak/k does not exceed 2 per cent. The most probable value of Aklk is insignificantly different from zero. A comparison is made with results on the variation of k inside the Earth from Birch’s finitestrain formulae; Birch’s results appear to be wholly reconcilable only with difficulty with results on k on Bullen’s approach. The present calculations suggest that one of three possibilities is the case: (i) Birch’s formulae fall a little short of fitting conditions near the Earth’s mantle-core boundary; or (ii) the chemical compositions of the lower mantle and outer core are less different than Birch and some others have thought likely; or (iii) the average temperature gradient is rather higher and the average density gradient appreciably lower inside the lower mantle than has been considered likely in most earlier calculations of Bullen. To meet the numerical requirements of the present calculations, the possibility (iii) would appear to require a fairly extreme combination of circumstances.

An automatic grading scheme for simple programming exercises

Abstract: A discussion is given of alterations that were made to a typical university operating system to record the results of programming exercises in three different languages, includeing assembly language. In this computer-controlled grading scheme provision is made for testing with programmer-supplied data and for final runs with system-supplied data. Exercises run under the scheme may be mixed with other programs, and no special recognition of exercises by the operators is necessary.

On the embryology of the cirripede crustaceans Tetraclita rosea (Krauss), Tetraclita purpurascens (Wood), Chthamalus antennatus (Darwin) and Chamaesipho columna (Spengler) and some considerations of crustacean phylogenetic relationships

Abstract: The relatively small but densely yolky eggs of balanomorph cirripedes undergo a bilaterally modified spiral cleavage, in which the yolk is confined within a single large cell, 4D, and the yolk cell becomes almost completely enclosed by yolk-free blastomeres as cleavage proceeds to the 33-cell stage. The cleavage sequence is similar in all four species, in spite of differences in the egg size. Presumptive areas are established at the 33-cell stage. The yolk cell 4D, exposed at the surface only postero-ventrally, is presumptive midgut. The cells 3A, 3B and 3C, lying at the surface ventrally in front of the exposed area of the presumptive midgut cell, are presumptive mesoderm. The remainder of the surface layer is presumptive ectoderm, comprising presumptive protocerebral ectoderm anteriorly, naupliar segmental ectoderm laterally, post-naupliar ectoderm posteriorly and temporarily attenuated ectoderm covering the yolk dorsally. A small area of presumptive stomodaeum lies midventrally at the presumptive antennal level. The presumptive midgut cell divides into a pair of yolky anterior midgut cells internally and a pair of small posterior midgut cells postero-ventrally at the surface. The latter migrate in, then posteriorly behind, the anterior midgut rudiment. The anterior midgut rudiment develops as the stomach of the nauplius, through cell division and gradual resorption of yolk. The posterior midgut rudiment develops through cell division as the intestine of the nauplius. The three mesoderm cells migrate inwards, then posteriorly and begin to divide. The products of their divisions concentrate as a posterior mass of mesoderm, from which paired mesodermal bands are proliferated forwards on either side of the anterior midgut. The bands concentrate as paired naupliar somites, which differentiate as naupliar muscles, and also as ventral stomodaeal and labral mesoderm. The residual posterior mass forms post-naupliar mesoderm, including paired groups of mesoteloblasts of the trunk somites. There are no preantennulary somites. The presumptive ectodermal areas develop directly into protocerebral and labral, antennulary, antennal, mandibular and post-naupliar surface epithelium, the latter forming the surface layer of a caudal papilla enclosing the residual post-naupliar mesoderm and the posterior end of the posterior midgut. The ventral naupliar ectoderm in front of, on either side of and behind the labrum and stomodaeum also proliferates the cells of the naupliar central nervous system. Only the mandibular proliferation can be recognized as a distinct ganglion. The dorsal ectoderm becomes temporarily attenuated over the mass of yolky anterior midgut cells, but is contracted and incorporated into the general dorsal epithelium of the naupliar region during later development. A comparison of the formation and fates of presumptive areas in Crustacea reveals that the cirripede mode of development exemplifies a basic developmental pattern for Crustacea. Modifications of development in other groups of crustaceans are all secondary functional adaptations related to the storage and exploitation of yolk during embryonic development. Radial cleavage in the small eggs of some cladocerans, copepods and penaeid malacostracans is a secondary modification of an ancestral spirally-based cleavage in Crustacea. The embryonic development of Crustacea, although based on spiral cleavage, differs fundamentally from the basic embryonic development of the onychophoran-myriapod-hexapod assemblage of arthropods, supporting the hypothesis of polyphyletic origin of the arthropods.

Metabolism of camphors and related compounds.

Abstract: 1. The metabolism of (+/-)-norcamphor, (+)-camphor, (-)-camphor, (+)-epicamphor, (+/-)-camphorquinone, (+/-)-camphane-2,5-dione and camphane was investigated in rabbits. All the compounds except camphane-2,5-dione increased the content of glucuronide in the urine. 2. (+/-)-Norcamphor was reduced to endo-norborneol; (+)-camphor, contrary to expectation, was reduced to (+)-borneol, as well as being hydroxylated to (+)-5-endo-hydroxycamphor and (+)-3-endo-hydroxycamphor, 5-endo-hydroxycamphor being the predominant product. (+)-Epicamphor was reduced mainly to (+)-epiborneol; (+/-)-camphorquinone gave 3-endo-hydroxycamphor and 2-endo-hydroxyepicamphor, the former being the major metabolite. (+/-)-Camphane-2,5-dione was reduced to 5-endo-hydroxycamphor. Camphane was hydroxylated to borneol and epiborneol, the latter predominating. 3. An explanation of these findings is given in terms of steric hindrance and thermodynamic stability. 4. The possibility was investigated that NADH was involved in the reductions.