Showing papers by "University of Adelaide published in 1968"
TL;DR: It is postulated that a successful crop ideotype will be a weak competitor, relative to its mass, and the like plants in the crop community will compete with each other to a minimum degree.
Abstract: Most plant breeding is based on “defect elimination” or “selection for yield”. A valuable additional approach is available through the breeding of crop ideotypes, plants with model characteristics known to influence photosynthesis, growth and (in cereals) grain production. Some instances of the successful use of model characters of this kind are quoted.
1,144 citations
TL;DR: In this article, the authors investigated the reasons for local minima in constrained optimization problems, and suggested methods leading to the global minimum, which can not be improved by iterative and gradient methods.
195 citations
TL;DR: Renin-LIKE enzymes have been extracted from a variety of tissues other than the kidney, including cat placenta1, rabbit uterine muscle and Placenta2–4, hog aorta5 and mouse submaxillary gland.
Abstract: RENIN-LIKE enzymes have been extracted from a variety of tissues other than the kidney, including cat placenta1, rabbit uterine muscle and placenta2–4, hog aorta5 and mouse submaxillary gland6,7.
161 citations
TL;DR: It is suggested that chorion is the source of renin in human amniotic fluid and that decidua, by limiting outward diffusion effectively, promotes intra-amniotic accumulation.
151 citations
TL;DR: The tomato spotted wilt virus (TSWV) as discussed by the authors was the first plant virus that was shown to contain lipid as an integral part of the virus, and it was found that much of the variation in symptoms was due to the differences in the proportion of each strain present.
Abstract: Publisher Summary The chapter discusses the time tomato spotted wilt virus (TSWV). One of the outstanding features of TSW is the great variety of symptoms seen and variability of the symptom picture even on the dame host. It varies from host to host, but for any one host (such as tomato or tobacco) it varies with the age of the infected plant, the level of nutrition, and particularly with environmental conditions, especially temperature. Later, with the discovery of the existence of strains of the virus, it became clear that much of this variation in symptoms was due to the differences in the proportion of each strain present. The great variation in the symptom-picture raised the possibility of the existence of strains, but differences in the environment, especially of temperature and host, caused such big differences in symptoms that they ascribed all such differences to changes in environment. Chemically, TSWV is a ribonucleic acid (RNA) virus, and was the first plant virus shown to contain lipid as an integral part of the virus. It contains about 20% lipid and 7% carbohydrate (in addition to the ribose of the RNA). Diversions and derangements in metabolism of TSWV-infected plants include an enhanced pool of free amino acids; the accumulation of a W-fluorescent phenyl propane derivative, 6-methoxy-7-hydroxy-1,2-benzopyrone (scopoletin), which appears to be an important link in the intermediary metabolism of the plant cells, and is linked with the growth hormone action; the production of a phenol oxidase enzyme in virus-invaded tissues; and a destruction of auxin. The most serious attempts to control the effect of virus activity in economic crops have been based on breeding resistant varieties, but so far with little success.
112 citations
TL;DR: The soft-bodied fauna can be grouped naturally into two categories, "non-resistant" and "resistant" as discussed by the authors, and fossils occur in negative relief on the bases of sedimentary laminae.
Abstract: With only two exceptions, this soft-bodied fauna can be grouped naturally into two categories, ‘non-resistant’ and ‘resistant’. Non-resistant animals (mostly medusoids) collapsed or decayed before diagenesis had set the enclosing sediment; fossils occur in convex relief on the depositional bases of sandstone laminae. Resistant animals (most annelids, pennatulids, and unique groups) supported the covering sediment until it had set; fossils occur in negative relief on the bases of sedimentary laminae. Where there was little clay between adjacent quartzitic laminae, counterpart moulds or counterpart casts are also found on tops of underlying laminae.
111 citations
TL;DR: In this paper, the analysis of a moving random pattern is considered for the case where the whole pattern can be recorded, and the pattern is assumed to have a certain mean velocity, and also to change randomly in form as it moves.
107 citations
TL;DR: In this paper, the results showed that most of the free iron oxides in these soils are present as small particles having little effect on the physical properties of the soil, while the control treatments decreased the stability of aggregates, increased the proportion of clay and silt but had little effect in the swelling.
Abstract: Summary
Red soils representing the major groups in which iron oxides are thought to exert a favourable effect on physical properties, have been treated with Na-dithionite and citrate, or Na-dithionite and 0.05 n HC1. These treatments removed the free iron oxides and some aluminium oxides and silica. Changes in the physical properties of the soils were measured by permeability, wet-sieving, mechanical dispersion, and swelling methods. These were compared with the changes induced by corresponding control treatments in which the soils were treated with Na2SO4 and Na-citrate, or Na2SO4 and 0.05 n HC1. The control treatments extracted some aluminium oxide and minor amounts of iron oxides and silica. In general, the control treatments decreased the stability of aggregates, increased the proportion of clay and silt but had little effect on the swelling. The treatments, which removed all the free iron oxide, caused no changes in excess of those due to the controls. The specific surface areas of samples treated with dithionite and acid, or sulphate and acid were determined by nitrogen adsorption methods. Removal of free iron oxides led in all but one instance to a reduction in the specific surface area, whereas sulphate and acid invariably increased the specific areas of the samples. The results show that most of the free iron oxides in these soils are present as small particles having little effect on the physical properties of the soil. The changes in physical properties brought about by dilute acid treatment indicate that the ‘active’ oxides in these soils are composed partly or wholly of the aluminium, iron, and silicon oxides which are readily soluble in dilute acid.
102 citations
TL;DR: Three Salmonella minnesota rough mutants were found to be more sensitive to the bactericidal action of antibody and complement than was the parent smooth strain.
Abstract: Three Salmonella minnesota rough mutants were found to be more sensitive to the bactericidal action of antibody and complement than was the parent smooth strain. The antibodies involved were shown to be against components which are all present in the smooth parent strain and are not identical with the lipopolysaccharides isolated by the phenol-water extraction procedure. The lipopolysaccharide of the smooth strain was shown to confer resistance by blocking access of antibody to the sensitive antigens.
98 citations
TL;DR: An examination of the distribution of protease between extra- and intracellular phases in washed cells showed the absence of any significant pool of preformed enzyme accumulating inside the cell over a 3-h period.
89 citations
TL;DR: Isolated pea chloroplasts undergo both cyclic and non-cyclic electron flow, and ADP-governed photosynthetic control' was shown to be dependent on the intactness of the chloroplast.
Abstract: Isolated pea chloroplasts undergo both cyclic and non-cyclic electron flow Both processes are coupled to photophosphorylation During non-cyclic flow the rate of oxygen production showed ADP-governed ;photosynthetic control' analogous to respiratory control of isolated mitochondria Measurements of ADP/O and photosynthetic control ratios yielded values of 1-13 and 2-57 respectively ;Photosynthetic control' was shown to be dependent on the intactness of the chloroplasts
TL;DR: In this article, electron-microscope studies of the clay fractions of red soils have shown that free iron oxides are present as small (50-100 A diam) discrete particles frequently clustered to form larger irregular aggregates.
Abstract: Summary
Electron-microscope studies of the clay fractions of red soils have shown that free iron oxides are present as small (50–100 A diam) discrete particles frequently clustered to form larger irregular aggregates. Although no evidence of iron-oxide coatings on clay minerals was found, an association of some of the oxide particles with the edges, but not the faces of kaolinite plates was observed.
01 Jan 1968
TL;DR: The most active area in the continent is the Adelaide seismic zone and the epicentres follow quite closely the trend of the Flinders and Mt Lofty Ranges, and appear to be associated with the South Australian rift zone.
Abstract: Data on Australian earthquakes up to 1966 are presented. The most active area in the continent is the Adelaide seismic zone. The epicentres follow quite closely the trend of the Flinders and Mt Lofty Ranges, and appear to be associated with the South Australian rift zone. Some seismic zones such as that in southwestern Australia may be associated with structural boundaries at depth in the crust and upper mantle. On the other hand there is little seismicity along some marked faults such as the 1000‐km long Darling Fault in Western Australia. All reliable depth determinations for Australian foci so far place them within the crust, mostly the upper crust. Such shallow crustal continental earthquakes should perhaps be regarded as a special class.
TL;DR: Apart from a highly significant difference in performance between the sides in favour of the preferred hand, this task showed, as did the typewriting task, a marked positive correlation between the performance levels of the two sides.
Abstract: The performance of two groups of 20 trained touch typists and one group of 20 nontypists was tested on seven different typewriting exercises. Three of these exercises were executed entirely with th...
TL;DR: The m/e 165 ion (C 13 H 9 ) has been noted in the mass spectra of a variety of heterocyclic systems containing two (or more) phenyl substituents as mentioned in this paper.
TL;DR: A particulate nitrate reductase has been prepared from actively denitrifying cells of Pseudomonas Denitrificans and contains flavin, sulphydryl groups and a metallic component(s) reduces NO3− stoichiometrically to NO2−.
TL;DR: This chapter covers recent work on the physiology of development of early parasitic stages from the infective stage, which may lead to a more general understanding of the relationship of the parasite to its host and help to explain the phenomenon of parasitism.
Abstract: Publisher Summary This chapter covers recent work on the physiology of development of early parasitic stages from the infective stage. There is now much evidence to support the view that the infective stage (in nematodes which infect the host per os) must receive from the host a stimulus which induces early developmental changes. It is presumed that the stimulus acts on a “receptor” of the infective stage and leads to possible neuro-endocrine activity which directly or indirectly affects target areas concerned in development. This area of research is of special interest because it may lead to a more general understanding of the relationship of the parasite to its host and help to explain the phenomenon of parasitism. Moreover, the early development from the infective stage may provide a useful model for the study of the control of differentiation. The concept of a “receptor” in this context is a broad one. It could be a discrete structure (e.g. a chemical sensory organ) or, more likely, it could refer to a compound or group of compounds distributed more widely in certain cells (e.g. some neurones or the nuclei of some cells) in the organism.
TL;DR: It is suggested that IAA could be the universal cause of cecidogenesis by plant-bugs, and that the specificity of gall-morphology is explicable in terms of the insects' behaviour.
TL;DR: The mass spectra of 22 benzimidazoles are reported and discussed in this paper, where the basic fragmentation patterns have been substantiated by deuterium labelling, exact mass measurements and appropriate metastable ions.
TL;DR: It is suggested that the torpor-mechanism may have evolved in two species of insectivorous marsupial mice to meet temporary or seasonal shortages of food.
Abstract: Body-temperatures in two species of insectivorous marsupial mice (family Dasyuridae) were measured using a rectal thermistor. In Sminthopsis crassicaudata at 21°C, body-temperatures ranged from–5–31 -1°C (432 measurements on 12 mice). A diurnal temperature cycle with a mean amplitude of 0.79°C was revealed, with temperatures at a maximum at 02.00 hours and a minimum at 10.00 hours. Mean body-temperatures of sibs showed significant differences; in one litter a difference of 2.7°C was demonstrated. In S. larapinta, the diurnal temperature cycle was greater with a mean amplitude of 4.24°C. Body-temperatures ranged from 38.8–22.9°C.
Changes in surface-temperature (Ts) in unrestrained animals during entry into and arousal from torpor, were measured using thermocouples fitted inside the nest-box and a recording potentiometer. S. larapinta had a daily torpor with or without food at room temperature, while in S. crassicaudata torpor could only be induced by lack of food. The lowest Ts reached were 18° and 17°C respectively. It is suggested that the torpor-mechanism may have evolved in these species to meet temporary or seasonal shortages of food.
TL;DR: This article offers a contribution to the theory of traffic distribution and presents some experimental results for comparison with the theory.
Abstract: This article offers a contribution to the theory of traffic distribution and presents some experimental results for comparison with the theory.
TL;DR: It follows that females are inseminated in autumn and store sperm until they ovulate in spring, and males' testes are small and without sperm in the spring, enlarge to a maximum in late summer, and decrease in the winter.
Abstract: Female Hemiergis peronii ovulate in the spring; males' testes are small and without sperm in the spring, enlarge to a maximum in late summer, and decrease in the winter. Females' oviducts contain sperm over the winter. It follows that females are inseminated in autumn and store sperm until they ovulate in spring.
TL;DR: The close association of centripetal and centrifugal systems suggests that bulbar activity is under the influence of sensory feedback systems, as well as more central control.
TL;DR: Investigations have revealed that sheep kidney pyruvate carboxylase possesses a lysine residue whose integrity is essential for enzymic activity, and the ability of the allosteric effector, acetyl-CoA, to protect the enzyme against inhibition by these reagents suggested that the e-amino group of lysines may be involved in the enzyme-acetyl- CoA interaction.
TL;DR: It is suggested that in a proportion of patients with pernicious anaemia the reduction in the number of mononuclear cells containing IgA may be primary and predispose to gastric mucosal damage.
TL;DR: It was shown that 30–50% of the viral ribonucleic acid (RNA) is released from QCMV incubated for 1 hour and that on longer incubation the suspension increases in turbidity, which appears to be caused by precipitation of viral protein.
TL;DR: T. punctatus is a sand-beach isopod which successfully orients on the beach by day or night, and its ability to orient by sun, moon, wind and slope of the substrate is tested.
TL;DR: The mass spectra of a variety of alkyl and aryl oxazoles have been determined and the spectra analyzed with the aid of deuterium labelling and high resolution mass spectrometry as discussed by the authors.
Abstract: The mass spectra of a variety of alkyl and aryl oxazoles have been determined and the spectra analyzed with the aid of deuterium labelling and high resolution mass spectrometry. In contrast to the corresponding benzenoid compounds, the mass spectra of isomeric alkyl oxazoles are distinctive and in this respect are akin to those of the corresponding pyridines. Further analogy to the pyridines is suggested by the unfavorable nature of a carbonium ion adjacent to the 2-position and this effect may be used to locate alkyl substituents attached to the oxazole nucleus. The loss of carbon monoxide from the molecular ions of 2,5-disubstituted oxazoles probably occurs with ring opening and migration of the C-5 substituent (e.g.Br) to the C-4 position.