Showing papers by "La Trobe University published in 1976"
TL;DR: In this paper, the 13-C NMR spectra for a number of dihydroflavones, dihydronols, flavonols, chalcones, and several glycosides in DMSO-d 6 solvent are reported and analysed.
237 citations
TL;DR: In this article, the C-NMR spectra of hydroxylated flavones and flavonols are presented for the first time and the accepted substitution additivity rules have been shown to hold for these compounds except in cases where structural modifications involve the C 3, 4 and 5 positions.
204 citations
TL;DR: A critical review of some relevant literature concerning the effects of prenatal administration of drugs and several other substances on postnatal behavior shows sufficient data exist to indicate that this will continue to be a viable and important area of research in the future.
Abstract: A critical review of some relevant literature concerning the effects of prenatal administration of drugs and several other substances on postnatal behavior. Significant variables and problems in the adequate design of experiments to assess these effects are discussed. Although the evidence concerning prenatal drug effects on behavior is equivocal, sufficient data exist to indicate that this will continue to be a viable and important area of research in the future. Present results demonstrate the complexity of drug interactions with other variables.
133 citations
105 citations
TL;DR: In this article, the motion of charged particles is examined in the case of a homogeneous magnetic field B together with an orthogonal electric field E, which has a gradient ▽E parallel to B. If B 2 q 2 m 2 − q▽E m > 0, the particles drift at right angles to E and B with a modified gyrofrequency and produce a current in that direction.
104 citations
TL;DR: In this paper, a linear relationship was found between nitrite concentration and the absorbance at 580 nm of the chromium (III) species produced, which was used to determine the nitrite.
83 citations
TL;DR: The Jindabyne Thrust has been mapped south of Lake Eucumbene, along the eastern side of Lake Jindabane and thence southwards to the gorge of the Snowy River in Byadbo Lands.
Abstract: The Jindabyne Thrust has been mapped south of Lake Eucumbene, along the eastern side of Lake Jindabyne and thence southwards to the gorge of the Snowy River in Byadbo Lands. It is marked by a crush...
78 citations
TL;DR: Drosera whittakeri was grown in sand cultures supplemented with inorganic salt solutions lacking either nitrogen, sulphur, phosphorus or the microelements andOptimum growth of Drosera binata was attained by applying insects to plants raised on nitrogen-free medium; addition of inorganic nitrogen to the nutrient solution to plants raise under these conditions inhibited growth.
Abstract: SUMMARY
Drosera whittakeri was grown in sand cultures supplemented with inorganic salt solutions lacking either nitrogen, sulphur, phosphorus or the microelements. Application of the insect Drosophila melanogaster to the tentacles of plants raised on nitrogen or sulphur deficient medium, enhanced growth, which on nitrogen deficient medium was accompanied by decreased nitrogen content per unit weight although the total nitrogen per plant was unaffected. Application of insects to plants on media deficient in phosphorus or the microelements had no effect on growth but significantly increased the phosphorus content of plants grown on a complete nutrient solution or media deficient in phosphorus or nitrogen. Insects would not serve as a heterotrophic carbon source for the realization of maximum growth of plants grown at very low light intensities.
Optimum growth of Drosera binata (and usually D. whittakeri) was attained by applying insects to plants raised on nitrogen-free medium; addition of inorganic nitrogen (as nitrate) to the nutrient solution to plants raised under these conditions inhibited growth. Optimum growth was not achieved by growing plants on a complete nutrient solution in the absence of insects.
Up to 50% of the phosphorus in the tubers of D. whittakeri occurred as inositol hexaphos-phate. Phosphorus was rapidly transferred to the growing parts of the plant on emergence. During the growing season, plants with higher than average phosphorus content developed new rhizomes on which new tubers formed. The indigenous distribution of Drosera species in southeastern Australia is not restricted to soils of very low phosphorus, nitrogen and sulphur status.
77 citations
TL;DR: Two of the 33 strains tested express neither F nor S, but do express a faintly staining PGK band which is of slightly faster mobility than F and which is absent from the other stains, which may represent a third allelic isozyme of PGK-B with reduced enzyme activity.
Abstract: Mammals possess two genetically distinct forms of phosphoglycerate kinase (PGK). Only the X-linked PGK-A isozyme is detectable by electrophoresis of somatic and ovarian tissues of the mouse and of most other eutherian mammals studied to date. The PGK-B isozyme is highly active in testes and epididymides which contain spermatozoa, as well as in semen. PGK-B activity is first detectable in testes of 22-day-old mice and shows rapid increase concomitant with germ cell proliferation until day 40, after which activity increases only slightly. Two allelic isozymes (F and S) in mice express equal enzyme activity and are inherited in an autosomal codominant manner. One is equally as heat stable as PGK-A; the other is heat labile. Two of the 33 strains tested express neither F nor S, but do express a faintly staining PGK band which is of slightly faster mobility than F and which is absent from the other stains. This may represent a third allelic isozyme of PGK-B with reduced enzyme activity.
75 citations
TL;DR: Observations are interpreted in terms of the action of metals on the oxidative and reductive steps in the biosynthetic pathway of pigments, while Mercury solutions markedly enhance protochlorophyll levels in young cultures, while decreasing chlorophyll a/b and pheophytin a/ b ratios.
67 citations
TL;DR: It is concluded that there may be either quantitative or qualitative differences in drug effects when schedule induced drinking is compared with deprivation induced drinking.
Abstract: Adjunctive or schedule induced behavior can be defined as an increase in the frequency of occurrence of an unreinforced behavior in the presence of conditions requiring an intermittent reinforced response, compared with the frequency of that behavior when no intermittent response is required. Although recognition has been given to the occurrence of other schedule induced behaviors it has most frequently been studied as schedule induced polydipsia in a rat on a food delivery schedule. In the present paper recent work on other schedule induced behaviors is reviewed including behaviors occurring in conjunction with nonconsumatory schedule parameters. These range from wheel running in the rat to game playing and maze solving in humans. This paper is also concerned with the review of pharmacological variables including the effects of peripheral and central administration. It is concluded that there may be either quantitative or qualitative differences in drug effects when schedule induced drinking is compared with deprivation induced drinking. A general activation theory [61] that adjunctive behavior is the result of an increase in the excitability of motor pathways which lead through the lateral hypothalamus can account for the data presented in this and earlier reviews but is too broad in its conception to make specific predictions about the relationships between schedule induced and schedule controlled behavior.
TL;DR: After an initial rapid uptake of mercury and zinc by cells, it appears that the daughter cells are able to regulate and prevent the further entry of these heavy metals into the biomass.
TL;DR: Evidence from 65 Zn uptake studies indicate that resistance is accompanied by an inhibition of the temperature sensitive component of zinc uptake and by a reduction in the number of exchange sites available for zinc in the free space (cell walls) per unit dry weight of the cells.
TL;DR: It is suggested that the type of flight “dimorphism” of E. postvittana which is associated with the size of the insect has survival value in enabling the moth to disperse when habitats become adverse for breeding.
Abstract: Adult males and females of the light brown apple moth,Epiphyas postivittana (Walk.) (Tortricidae) showed seasonal, cyclic variations in size at two study areas. These variations are caused by the quality of the food available and temperature. Large individuals occur during the cool wet months of the year (autumn-winter generation moths that fly during September-November) and small individuals occur during the warm dry months of the year (from January to May when late-spring and summer generation moths fly). The ratios of body length to wing-length showed that the wing-loadings of the smaller individuals are significantly lower than those of large individuals, even though the latter have longer wings. Those with low wing-loading would be expected to be more adapted for dispersal. It is suggested that the type of flight "dimorphism" ofE. postvittana which is associated with the size of the insect has survival value in enabling the moth to disperse when habitats become adverse for breeding.
TL;DR: In this paper, the thermal decomposition products of copper dimethyldithiocarbamate and copper diethyldithium carbamate have been semi-quantitatively analyzed by a combined gas chromatography-based technique.
Abstract: The thermal decomposition products of copper dimethyldithiocarbamate and copper diethyldithiocarbamate have been semi-quantitatively analyzed by a combined gas chromatography — mass spectrometry technique and thermal decomposition mechanisms for both complexes are proposed. The fragmentation pathway is strongly influenced by the nature of the terminal alkyl group attached to the dithiocarbamate moiety.
TL;DR: The results indicate that, in addition to the selection of an effective dose, it is also possible to choose a site of injection which will produce a maximal area of specific depletion, and where injections into terminal areas caused limited specific depletion the same dose injected into preterminal axons often caused a more widespread loss of fluorescence.
Abstract: Fluorescence histochemistry was used to assess monoamine depletion after injections of 6-OHDA into selected brain areas. Two volumes (2 and 4 μl) and 4 concentrations (1, 2, 4 and 8 μg/μl) of 6-OHDA were injected into the olfactory tubercle, the posterior lateral hypothalamus and the lateral hypothalamus. Selective destruction of catecholamine-containing neurons resulted from all injections of 6-OHDA with the exception of the 2 lowest doses (2 and 4 μl of 1 μg/μl) and the highest dose (4 μl of 8 μg/μl) which produced nonspecific damage of brain parenchyma. The results indicate that, in addition to the selection of an effective dose, it is also possible to choose a site of injection which will produce a maximal area of specific depletion. In cases where injections into terminal areas caused limited specific depletion the same dose injected into preterminal axons often caused a more widespread loss of flourescence. With volume, concentration and anatomical location being important variables to consider, caution is needed in the interpretation of behavioural experiments. When using 6-OHDA it is necessary to show that specific depletion of catecholamines has been achieved.
TL;DR: Evidence for chemical homology together with the previously reported immunochemical crossreactivity for these isozymes provide evidence that the A and B polypeptides are products of recently duplicated genes during evolution.
Abstract: l-α-Hydroxyacid oxidase isozymes from rat liver (A isozyme) and kidney (B isozyme) have been isolated in a high state of purity with specific activities of 61 and 14.7 microkatals per gram protein respectively. The subunit molecular weights determined by sodium dodecylsulphate polyacrylamide gel electrophoresis were 40000 ± 3000; the mouse A and B isozymes were also partially purified and their subunit molecular weights shown to be 37000.
The total amino acid contents of the two rat isozymes were very similar and had identical tyrosine (9 residues per 40000) and tryptophan (5 per 40000) contents. No free suiphydryl groups were found following suiphydryl titration experiments using the purified native rat isozymes. Following denaturation with sodium dodecylsulphate, 2 (A subunit) and 3 (B subunit) suiphydryl residues were titratable. The apoenzyme form of rat isozyme B exhibited 2 of the 3 titratable suiphydryl groups in the absence of sodium dodecylsulphate which suggests an involvement of these residues in coenzyme binding. Flavin mononucleotide content was estimated from spectral studies to be I residue per subunit (40000 molecular weight) of native enzyme. Following storage in ammonium sulphate at 4°C for several months, flavin mononucleotide was irreversibly removed such that the rat A and B isozymes contained 0.3 and 0.7 residue of coenzyme per subunit. This accounts for the more pronounced loss of specific activity following storage for the A isozyme than the B isozyme as well as the comparatively high minimal molecular weights based upon flavin mononucleotide values previously reported by other workers.
This evidence for chemical homology together with the previously reported immunochemical crossreactivity for these isozymes provide evidence that the A and B polypeptides are products of recently duplicated genes during evolution.
TL;DR: Diphenylhydantoin (DPH), which stimulates Na(+)-K(+-ATPase activity, overcomes ouabain- and CXM-induced amnesia but not LiCl- or KCl- induced amnesia.
TL;DR: Analysis of data obtained from 80 first year university students of middle-class and working-class origin indicated that, in relation to oral systems, written systems were more complex in structure; revealed more adjectival but less adverbial elaboration; showed more complex verb structures but contained fewer indices of personal reference.
Abstract: Data obtained from 80 first year university students of middle-class and working-class origin were used to explore aspects of the relationships between oral and written language systems. Subjects p...
TL;DR: Data show that the scheduling of cognitive tasks can also lead to adjunctive behavior, and a comparison with baseline conditions showed an increase in the amount of subjects' motor activity under schedule conditions.
TL;DR: Freeze-substitution using a mixture of 20% acrolein in diethyl ether preserves ultrastructural integrity and does not cause significant losses of diffusable ions from samples of tissues labelled with 22Na, 86Rb and 36Cl.
TL;DR: Four gene products involved in the enzymatic synthesis of enterochelin from 2,3-dihydroxybenzoate, L-serine and ATP have been partially purified using a previously reported fractionation procedure and certain properties and functions of the four semi-purified components have been investigated.
TL;DR: The amount of flight activity and the amount of rainfall were negatively correlated; flights did not occur when the daily precipitation exceeded 32.5 mm, and with a precipitation exceeding 39 mm no flights could be expected.
Abstract: The flight activity of Epiphyas postvittana was studied at two sites near Melbourne with the aid of suction traps, over a period of 4 years. Maximum numbers were found to fly during the period September to March with peak activity coinciding with the emergence of winter, spring and summer generation moths. E. postivittana is predominantly a nocturnal flier with maximum activity around 20.00–24.00 h. The lower temperature threshold of flight was 8–11°C. The upper temperature threshold varied from 20–21°C, 24–25°C and 27–28°C for the winter, spring and summer generation moths respectively. Flight was highly influenced by the prevailing wind. The lower wind speed threshold was 0.5–0.8 m-s and the upper wind speed threshold was 2.6–2.7 m-s. The relationship between wind speed and the amount of flight was non-linear, with the frequency of flights decreasing sharply with increasing wind speed. No flights occurred at wind speeds greater than 2.8 m-s. Variation in relative humidity had no influence on flight, but lack of rain favoured flight. The amount of flight activity and the amount of rainfall were negatively correlated; flights did not occur when the daily precipitation exceeded 32.5 mm, and with a precipitation exceeding 39 mm no flights could be expected. The value of these findings to pest control programmes is discussed.
TL;DR: A modification of the model was presented to accommodate further findings that variations in both dose-level of administered physostigmine and initial learning ability influenced subsequent retention, depending on the training-testing interval.
Abstract: A series of experiments was designed to assess the effect of physostigmine on the retention of an appetitively-reinforced Y-maze discrimination. The results supported in part the model of cholinergic involvement in long-term memory as proposed by Deutsch, in that physostigmine respectively impaired and enhanced well-remembered and poorly-remembered responses. However a modification of the model was presented to accommodate further findings that variations in both dose-level of administered physostigmine and initial learning ability influenced subsequent retention, depending on the training-testing interval.
TL;DR: Amphetamine overcomes the amnesia caused by cycloheximide (CXM) provided it is administered closely following the learning trial, and it has been suggested that this labile memory trace depends on the functioning of a sodium pump.
Abstract: Amphetamine overcomes the amnesia caused by cycloheximide (CXM) provided it is administered closely following the learning trial. In day-old chickens with one trial passive avoidance learning, there is a short-term, labile memory existing for 90 min following training under the influence of CXM. Amphetamine has been shown to keep the memory at precisely the level exhibited by the labile, cycloheximide-resistant memory trace at the time of injection. Norepinephrine, methoxamine (an α adrenergic stimulant) and isoprenaline (a β adrenergic stimulant) each mimic the amphetamine effect in CXM-pretreated chickens. That the action of amphetamine could be due to its release of norepinephrine is supported by the finding that it could be blocked by both α adrenergic (piperoxane) and β adrenergic antagonists (propranolol). It has been suggested that this labile memory trace depends on the functioning of a sodium pump. Norepinephrine may be modulating memory formation by an action on the sodium pump since in preliminary biochemical assays norepinephrine stimulated the sodium pump (Na + /K + ATPase) activity in chicken forebrain total homogenate.
TL;DR: In this paper, the mean of the offspring distribution of a supercritical Galton-Watson process was investigated and the maximum likelihood estimator was shown to be not an optimum discriminator between alternative values of the parameter.
Abstract: SUMMARY This paper is concerned with efficiency in testing for the mean of the offspring distribution of a supercritical Galton-Watson process. It is suggested that the maximum likelihood estimator is generally inefficient for this problem in the sense that asymptotically it is not an optimum discriminator between alternative values of the parameter. Three competing tests are discussed and their efficiency compared via an example.
TL;DR: Chicks were trained to avoid pecking either a red or a blue bead in a one-trial avoidance task by coating one bead with methy anthranilate, and CXM- and ouabain-treated chickens showed loss of memory for the bead associated with the drug but showed retention of the task which was not associated withThe drug.
TL;DR: A recent survey revealed an accumulation of a variety of heavy metals in bottom sediments of the Port Phillip Bay as discussed by the authors, including cadmium, in oysters and mussels.
TL;DR: Data suggest that, provided there is sufficient labile memory in existence at the time of administration, amphetamine maintains the trace which would otherwise decay and allows it subsequent consolidation into permanent memory at a time later than normal.
Abstract: When the protein synthesis inhibitor cycloheximide (CXM) is administered just before or soon after a single learning trial, the formation of permanent memory is prevented in day-old chickens. In spite of the blockage of long-term memory, which occurs by 3 hr, Mark and Watts [14] have demonstrated a short-term memory which is independent of protein synthesis and which decays over the 3 hr period. D-amphetamine sulphate, administered subcutaneously (up to 2 hr) after learning to CXM pretreated chickens, held the memory at the level exhibited by the labile memory trace at the time of injection. This close relationship between the amount of labile memory and the time of injection was still apparent 24 hr after learning. These data suggest that, provided there is sufficient labile memory in existence at the time of administration, amphetamine maintains the trace which would otherwise decay and allows its subsequent consolidation into permanent memory at a time later than normal.