Showing papers by "La Trobe University published in 1975"
269 citations
199 citations
TL;DR: A new 1,3; 1,4-/Iglucan with these properties has been prepared and its use in studies on the specificity of /3- glucan endohydrolases is described.
158 citations
TL;DR: In this paper, the use of several alkylphosphoric acid esters in the production of PVC membranes for use as calcium-sensitive, coated-wire electrodes is reported.
102 citations
TL;DR: In this paper, the binding and separation energies of the outer electronic bands of the alkaline-earth fluorides were determined using 40.81-eV ultraviolet and Al $K\ensuremath{\alpha}$ (1486.6 eV) x-ray photoelectron spectrometry.
Abstract: Precise values have been determined for the binding and separation energies of the outer electronic bands of the alkaline-earth fluorides using 40.81-eV ultraviolet and Al $K\ensuremath{\alpha}$ (1486.6 eV) x-ray photoelectron spectrometry. Excellent agreement is found between the experimental and Born-model theoretical values for the energy separation between the outermost levels of the alkaline-earth and fluorine ions when the experimental values are corrected for relaxation (polarization) effects and when the Madelung energy alone is taken to represent the electron-lattice interaction. Very good agreement also occurs between experimental and theoretical values for the absolute binding energies. These results are accounted for by the fact that the substantial repulsive energy existing in the alkaline-earth fluorides is stored predominantly as interionic elastic potential energy and has little effect on the electronic energy levels on the ions. Comparison of the bandwidths of the alkaline-earth fluorides from the present work and alkali-metal fluorides from previous work shows that the ${\mathrm{F}}^{\ensuremath{-}}$ $2p$ valence-band width is a function of the nearest-neighbor distance and independent of the particular compound.
91 citations
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TL;DR: The thesis is that the right to life is a right possessed by persons and by certain potential persons, that its ground is and must be found in the nature of man, in man's autonomy.
Abstract: Although the issues with which this paper is concerned are of the greatest importance, the paper itself is a modest one which represents an attempt to bring together strands in contemporary Western thought about respect for human life. I am concerned with the basis of the right to life, whether all human beings possess it, and why, what the right involves and enjoins, what constitutes lack of respect for it, what are its limits, how, in what ways and to what degrees it is a prima facie or conditional right. The theme of the paper is an examination of the right to life with reference to the rationale of contemporary humanist thought on the matter. My thesis is that the right to life is a right possessed by persons and by certain potential persons, that its ground is and must be found in the nature of man, in man's autonomy, that it is not merely a negative right as Locke and so many since him have seen it as being, a right not to be killed, but a right to receive aids and facilities to protect and preserve one's life against dangers, humanly and naturally created, and that, being a right of recipience, it is a prima facie or conditional right, a right, the claims of which must on occasion be subordinate to the claims of other rights and values. What I am concerned to oppose is the view that all human beings possess the right to life, an absolute, inviolable, inalienable right to life at that.
89 citations
TL;DR: In this article, the authors reviewed the subject of joule dissipation of ionospheric currents and movement of the thermosphere by electric fields and compared the depositions of energy into the upper atmosphere by charged particles and electric fields.
70 citations
TL;DR: The method proposed by Nethercot for the determination of the Fermi energies and photoelectric thresholds of simple binary compounds has been successfully applied to some AB 2 compounds and metals as mentioned in this paper.
56 citations
TL;DR: This communication describes a mutant of Aspergillus nidulans that is altered in a site closely linked to the structural gene for acetamidase that results in increased inducibility of this enzyme by acetamide and it is shown that this mutation is cis-dominant in its effects.
Abstract: STUDIES on cis-acting regulatory mutants (for example, operator and promoter mutants) in bacteria have been of crucial importance in understanding gene regulation1–4 Similar mutants in eukaryote systems have not been extensively studied although there have been two reports of probable operator constitutive mutants in yeast5,6 An understanding of eukaryote genetic organisation and gene regulation requires that mutants affecting the regulation of adjacent genes of defined function be isolated and characterised This communication describes a mutant of Aspergillus nidulans that is altered in a site closely linked to the structural gene (amdS) for acetamidase (EC3514)7,8 and results in increased inducibility of this enzyme by acetamide It is further shown that this mutation is cis-dominant in its effects
55 citations
TL;DR: Water could not be extracted from near saturated air but was available from the soil when the soil water content was greater than 11%.
Abstract: The water loss from the wolf spider Geolycosa godeffroyi (L. Koch) is presented for a wide range of environmental conditions. Water loss is influenced by the size of the spider, temperature, saturation deficit and by relative humidity per se. The spiders thermoregulatory behaviour more than doubled water loss. Water could not be extracted from near saturated air but was available from the soil when the soil water content was greater than 11%. Due to the spiders burrowing habits both the active and passive use of heat differentials were potential sources of free water.
51 citations
TL;DR: There were large variations in the types and frequencies of behaviors emitted by different individuals, interpreted in terms of an increase in motor excitability which seems to occur in some individuals on certain schedules of reinforcement.
TL;DR: In this paper, seven copper(II) dithiocarbamate complexes [Cu(R 2 Dtc) 2 : R 2 = Me 2, Et 2, nPr 2, nBu 2, cycHex 2, Et Ph, pyrrol and pip] have been prepared and examined by thermogravimetric analysis (TG).
TL;DR: The entry of blue-green algae into an aerial root of Macrozamia communis via a break in the dermal layers and leading through a continuous cortical channel into the algal zone is reported.
Abstract: A B S T R A C T The entry of blue-green algae into an aerial root of Macrozamia communis via a break in the dermal layers and leading through a continuous cortical channel into the algal zone is reported. Penetration of the algae appears to be mainly in the form of filaments. Intercellular migration of the algae is found to occur after dissolution of host cell middle lamellae, but host cortical cells are also destroyed near some of the algae. Intracellular migration is also suggested to be a likely pathway for the algae as they proceed to the algal zone.
TL;DR: Three phosphodiesterases that are capable of hydrolysing 3':5'-cyclic nucleotides were purified from potato tubers and their possible significance in cyclic nucleotide metabolism in higher plants is discussed.
Abstract: 1. Three phosphodiesterases that are capable of hydrolysing 3':5'-cyclic nucleotides were purified from potato tubers. 2. The phosphodiesterases were fractionated by (NH4)2SO4 precipitation and CM-cellulose chromatography. The phosphodiesterases were resolved from each other and further purified by gel filtration in high- and low-ionic-strength conditions. 3. All three enzymes lacked significant nucleotidase activity. 4. Enzymes I and II had mol. wts. 240,000 and 80,000 respectively, determined by gel filtration, whereas enzyme III showed anomalous behaviour on gel filtration, behaving as a high- or low-molecular-weight protein in high- or low-ionic-strength buffers respectively. 5. All enzymes hydrolysed 2':3'-cyclic nucleotides as well as 3':5'-cyclic nucleotides. The enzymes also had nucleotide pyrophosphatase activity, hydrolysing NAD+ and UDP-glucose to various extents. Enzymes I and II hydrolyse cyclic nucleotides at a greater rate than NAD+, whereas enzyme III hydrolyses NAD+ at a much greater rate than cyclic nucleotides. All three enzymes hydrolysed the artificial substrate bis-(p-nitro-phenyl) phosphate. 6. The enzymes do not require the addition of bivalent cations for activity. 7. Both enzymes I and II have optimum activity at pH6 with 3':5'-cyclic AMP and bis-(p-nitrophenyl) phosphate as substrates. The products of 3':5'-cyclic AMP hydrolysis were 3'-AMP and 5'-AMP, the ratio of the two products being different for each enzyme and varying with pH. 8. Theophylline inhibits enzymes I and II slightly, but other methyl xanthines have little effect. Enzymes I and II were competitively inhibited by many nucleotides containing phosphomonoester and phosphodiester bonds, as well as by Pi. 9. The possible significance of these phosphodiesterases in cyclic nucleotide metabolism in higher plants is discussed.
TL;DR: It was argued that the physiological and behavioural unresponsiveness of the Imipramine offspring was due to a subtle teratogenic effect which prevented the Ss from interacting with the environment.
Abstract: Offspring of rats given oral doses of Saline or Imipramine (5 mg/kg) from 14–21 days prior to mating till parturition were reared, after weaning, in deprived or enriched environments. At 25–27 days and at 80–83 days the home cage behaviour of the Ss reared in the enriched environment was observed. Histological measures of brain development in both the deprived and enriched Ss were taken at the conclusion of behavioural observations. The Imipramine exposed offspring failed to show the characteristic histological changes associated with enriched rearing conditions. In addition they were behaviourally unresponsive and spent significantly less time than the Saline offspring interacting with other animals and the environment. It was argued that the physiological and behavioural unresponsiveness of the Imipramine offspring was due to a subtle teratogenic effect which prevented the Ss from interacting with the environment.
TL;DR: A continuous spectrophotometric method suitable for the determination of the activities of several peroxisomal oxidases in rat tissue homogenates is described and Catalase interference was overcome using azide to inhibit its activity.
01 Sep 1975
TL;DR: Rb, Sr and87Sr/86Sr have been determined for fragments of matrix and clasts from three hand-specimens of Boulder 1, 72275, 72255, and 72215 as discussed by the authors.
Abstract: Rb, Sr and87Sr/86Sr have been determined for fragments of matrix and clasts from three of the hand-specimens of Boulder 1, 72275, 72255, and 72215. Total-rock and certain plagioclase samples from a crushed norite clast (Civet Cat) define an age of 4.17±0.05AE (2σ) for the pre-Serenitatis igneous differentiation of the norite. Pyroxene and other mineral separates were affected by a later event at about 3.9±0.1AE. An unshocked clast of pigeonite basalt has a well-fitted mineral isochron of 4.01±0.04AE. Samples of the competent breccia matrix comparatively rich in small clasts of highly radiogenic microgranite define a mixing line equivalent to 4.03±0.03AE, which denotes the age of the microgranite. Other samples of the matrix dominated by small anorthosite clasts define a 4.4AE mixing-line and demonstrate that Sr isotope equilibration between plagioclase and matrix did not occur during the high-temperature event that indurated the matrix.
TL;DR: Female rats were given oral doses of Imipramine from 14-21 days prior to mating to conception or Day 19 or gestation and the physical maturation and behavioral development of their offspring was compared with that of controls.
Abstract: Female rats were given oral doses of Imipramine (5mg/kg) from 14–21 days prior to mating to conception or Day 19 of gestation and the physical maturation and behavioral development of their offspring was compared with that of controls. There were significant differences between the weights of the Impramine and control animals at 21 days and the appearance of some reflexes was delayed. Behavior in an open field was observed when the rats were 9, 13, 17 and 21 days of age and it was found that exploratory responses were less frequent in the drug exposed offspring. In contrast there were no obvious physical anomalies and the adult behavior of the Imipramine animals on a spontaneous alternation task and a swimming maze did not differ from that of controls.
TL;DR: Stark differences in extent of diffusion have been shown with the fluorescence histochemical method between guanethidine and 6-OHDA when injected acutely or chronically into the lateral hypothalamus, the substantia nigra or the amygdala of the rat brain when injected intracranially.
Abstract: Marked differences in extent of diffusion have been shown with the fluorescence histochemical method between guanethidine and 6-OHDA(64 mug in 2 mul) when injected acutely or chronically into the lateral hypothalamus, the substantia nigra or the amygdala of the rat brain. Cannulation damage up to 1 mm in diameter and attributed to the implantation of cannulae and placebo injection was observed. A further area of generalized damage occurred following the injection of drugs and was far greater for 6-OHDA (2 mm) than for guanethidien (0.3 mm). Guanethidine, but not 6-OHDA, caused specific damage to catecholamine-containing nerurons up to a distance of at least 3 mm and more from the cannula tip. These striking differences between the effects of intracranial injection of 6-OHDA and guanethidine are discussed in terms of the uptake and degradation of the two drugs and the anatomical features of the injection site; they are not explicable in terms of experimental conditions such as concentration, volume of injection, molecular weight or lipid solubility. The different patterns of damage would not easily be distinguished by biochemical analyses and the catecholamine specificity of 6-OHDA in studies of the central nervous system must be seriously questioned. Vascularization of chronically implanted cannula tracks and the presence of anatomical diffusion barriers are also discussed in relation to the diffusion of drugs injected intracranially.
TL;DR: When tested in both a Henderson-type maze and a swimming maze no behavioural effects due to prenatal drug exposure were observed and when the Ss were reared in a deprived environment the maze performance of those animals which had been exposed to imipramine or vitamin-A was significantly inferior to that of the control animals.
Abstract: Offspring of rats given oral doses of imipramine (5 mg/kg) from 14–21 days prior to mating till parturition or vitamin-A (100000 i.u./kg) between days 8 and 10 of gestation were reared, after weaning, in deprived or enriched environments. When tested in both a Henderson-type maze and a swimming maze no behavioural effects due to prenatal drug exposure were observed when the Ss were reared in a deprived environment. When the Ss were reared in an enriched environment the maze performance of those animals which had been exposed to imipramine or vitamin-A was significantly inferior to that of the control animals. The implications of these findings are discussed with respect to environmental interaction with prenatal drug effects on behaviour.
TL;DR: In this article, the interferences of a range of ions (including the hydrogen ion) on the potential responses of a series of coated-wire calcium-selective electrodes are discussed as a function of the composition of the PVC membranes.
TL;DR: The phototactic responses of four recently collected isofemale strains ofDrosophila melanogaster and D. simulans were measured in a light gradient from 590 to 10 lux, and within each species variability was found.
Abstract: The phototactic responses of four recently collected isofemale strains ofDrosophila melanogaster andDrosophila simulans were measured in a light gradient from 590 to 10 lux. High light intensities were preferred by most flies, but a small proportion of flies preferred the lowest light intensity. Based on the strains tested,D. simulans showed greater phototaxis thanD. melanogaster, and within each species variability was found. The niche breadth ofD. melanogaster appears likely to be greater than that ofD. simulans for phototaxis in the light gradient. These results are in general qualitative agreement with earlier results published on dispersal activities from the same populations.
TL;DR: The present paper is the first report of work on a unique learning situation which is based on the well-known mazes used to study taxes in Drosophila and involves no aversive stimulation.
Abstract: IF it could be demonstrated that Drosophila are able to learn, then our extensive knowledge of the genetics of this dipteran could be applied to understanding the biological bases of learning. Reports of learning in Drosophila1–3 sometimes involve changes in orientation as the result of aversive stimulation, for example, electric shock. The use of these stimuli can bring additional problems such as conditioned inhibition where the animals cease responding altogether4. The present paper is the first report of work on a unique learning situation which is based on the well-known mazes used to study taxes in Drosophila5 and involves no aversive stimulation.
TL;DR: A procedure is presented for the rapid purification of a 5′-nucleotidase (5′-ribonucleotide phosphohydrolase, EC 3.1.5) from potato tubers, involving ammonium sulphate fractionation and chromatography on phosphocellulose, DEAE- cellulose and Sephadex G-75.
TL;DR: In this article, a nonlinear least squares method for the calculation of spin-lattice relaxation times is described, which offers considerable time savings compared with current methods, as repetition times only up to the order of T1 are required.
TL;DR: In this article, necessary and sufficient conditions are obtained for the existence of an optimal solution, and appropriate duality theorems are established for this problem, where the objective function includes the square root of a quadratic form.
Abstract: Duality relations for various classes of complex nonlinear programming problems have recently appeared in the literaure These problems are special cases of a complex programming problem whose objective function includes the square root of a quadratic form, and so may not be differentiable For this problem, necessary and sufficient conditions are obtained for the existence of an optimal solution, and appropriate duality theorems are established
TL;DR: The results suggest that PD-induced frameshift mutations may arise in some other way, and two possible mechanisms involving sequential action of the excision repair and recombinational repair pathways are considered.
Abstract: Induction of back mutations to prototrophy by methylene blue (MB)-sensitized photodynamic (PD) treatment has been studied in wild-type and repair-deficient strains of Salmonella typhimurium carrying either the base-pair substitution mutation hisG46 or the frameshift mutation hisD3052. We found that reversion of the hisG46 mutation was increased in a strain carrying a uvrB deletion and decreased in a strain carrying a recA-type mutation. Reversion of the hisD3052 (frameshift) mutation, on the other hand, was decreased in both uvrB deletion and recA-type strains. The former results are consistent with the hypothesis that the majority of MB-sensitized PD-induced base-pair substitution mutations arise by a mechanism similar to that currently believed to be involved in UV mutagenesis. The latter results suggest that PD-induced frameshift mutations may arise in some other way, and two possible mechanisms involving sequential action of the excision repair and recombinational repair pathways are considered.
TL;DR: In this article, it was shown that an optimal solution for a nonlinear fractional programming problem can be obtained by solving two associated programming problems whose objective functions are no longer fractional.
Abstract: If an optimal solution exists for a nonlinear fractional programming problem, then this solution is shown to be obtainable by solving two associated programming problems whose objective functions are no longer fractional. A certain restriction is assumed on the constraint sets of the latter problems. This result includes various known theorems as special cases.