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Showing papers by "La Trobe University published in 1973"


Journal ArticleDOI
01 May 1973-Genetics
TL;DR: It is shown that migration from a more favorable regime to a less favorable regime is selected against and the ramifications for general modifier theory are discussed.
Abstract: Simple models for the genetic control of the tendency to migrate are considered. It is shown that migration from a more favorable regime to a less favorable regime is selected against. The ramifications for general modifier theory are discussed.

179 citations


Journal ArticleDOI
TL;DR: In this paper, an algorithm for the calculation of eigenvalues and eigenvectors of centrosymmetric and related matrices is given, and some desirable properties of the algorithm are proved.

139 citations


Journal ArticleDOI
TL;DR: Cicadas feed on xylem fluid which is hypotonic to the haemolymph and contains high concentrations of potassium, sodium, calcium, magnesium, chloride, and phosphate ions, and traces of amino acids are also found in urine.

93 citations


Journal ArticleDOI
01 Mar 1973-Planta
TL;DR: In species of Apium, Eryngium and Humulus, the cuticular membrane of the petiole could be resolved into two parts, of which the inner one appeared amorphous and after staining appeared to be penetrated by an electron-dense reticulum, whereas the outer layer showed a lamellate structure.
Abstract: In species of Apium, Eryngium and Humulus, the cuticular membrane of the petiole could be resolved into two parts, of which the inner one appeared amorphous and after staining appeared to be penetrated by an electron-dense reticulum, whereas the outer layer showed a lamellate structure consisting of electron-dense and electron-transparent plates, 50–80 A in thickness. These layers are considered to correspond with the cuticular layer and the cuticle proper, respectively. In species of Abutilon and Rumex the cuticle proper did not exhibit the lamellate structure. In the leaves of Eryngium the outer lamellated structure was present in the cuticle of both young and mature leaves. Both the lamellate and non-lamellate types of the cuticle proper increased in thickness with age of the specimen. The results are discussed in relation to earlier investigations.

59 citations


Journal ArticleDOI
01 Apr 1973-Mind

58 citations


Journal ArticleDOI
TL;DR: It was concluded that because the R-Utrecht factor does not restore uv resistance or uv mutability to the recA-type mutants, it seems unlikely that the effects of the R factor on the uv response of wild- type cells could be due to a plasmid gene whose product is functionally equivalent to that of the chromosomal recA.
Abstract: Derivatives of strains of S. typhimurium with and without H-Utrecht were tested for their ability to yield uv-induced back mutations of the amber mutation. Results showed that R-Utrecht significantly enhanced the uv mutability of one strain, but cells of another strain were stable to the mutagenic effects of uv whether or not R-Utrecht is present. It was concluded that because the R-Utrecht factor does not restore uv resistance or uv mutability to the recA-type mutants, it seems unlikely that the effects of the R factor on the uv response of wild- type cells could be due to a plasmid gene whose product is functionally equivalent to that of the chromosomal recA. (HLW)

55 citations


Journal ArticleDOI
TL;DR: The posterior midgut may be involved in ion secretion which could be related to filter chamber function and the cells are characterized by deep narrow basal invaginations and the absence of a mucoprotein coat investing the microvilli.
Abstract: The midgut of cicadoid and cercopoid insects is differentiated at the anatomical, ultrastructural and cytochemical levels into a conical segment, anterior, mid, and posterior midgut. The cells of the conical segment and anterior midgut are cytochemically very similar. They differ in ultrastructure, the anterior midgut cells having a submicrovillar row of mitochondria and a very marked mucoprotein coat investing the microvilli. The mid-midgut contains mineral spherites, which are formed in cisternae in the endoplasmic reticulum, and ferritin. The posterior midgut differs cytochemically from the anterior midgut and the cells are characterized by deep narrow basal invaginations and the absence of a mucoprotein coat investing the microvilli. It is suggested that nutrient absorption occurs in the conical segment and anterior midgut. Ion absorption may also occur in the anterior midgut. Storage excretion of calcium, magnesium and phosphate occurs in the mid-midgut. Ferritin is also stored here but may be found in other regions of the midgut, particularly in the cicada. The posterior midgut may be involved in ion secretion which could be related to filter chamber function.

51 citations


Journal Article
09 May 1973-Nature

51 citations


Journal ArticleDOI
TL;DR: In this paper, the electron impact induced ionization and dissociation of CH4 and SiH4 have been studied using a quadrupole mass spectrometer and deconvoluted first differential ionization efficiency curves are presented and structural features of the parent and fragment ion curves discussed in terms of their contribution to the total differential ionisation cross section.

50 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared the statistics on crime, imprisonment and mental illness from fourteen European countries and found a negative correlation between the proportion of people within a nation placed in mental hospitals and the proportion held in prison.
Abstract: It is over thirty years since Penrose (1939) compared the statistics on crime, imprisonment and mental illness from fourteen European countries and found a negative correlation between the proportion of people within a nation placed in mental hospitals and the proportion held in prison. In addition, using sentencing statistics and official returns on homicide, he reported that the amount of crime in a community (particularly crime involving violence) was positively related to the proportion of the community sentenced to prison. Juxtaposing crime, imprisonment and mental hos pitalisation rates, Penrose finally suggested that the evidence he had marshalled was consistent with the notion that the provision of facilities for mentally ill people lessened the incidence of crime, and, as a consequence, the numbers of people in prison were reduced. This connection rested upon his assumption that " insanity and mental deficiency are predisposing causes of crime."

46 citations


Journal ArticleDOI
TL;DR: Salmonella typhimurium LT2 hisG46 becomes a more sensitive strain for assaying mutagens and carcinogens when it carries the resistance transfer factor R-Utrecht.
Abstract: Salmonella typhimurium LT2 hisG46 becomes a more sensitive strain for assaying mutagens and carcinogens when it carries the resistance transfer factor R-Utrecht.



Journal ArticleDOI
TL;DR: It was concluded that adenosine 3'-phosphate 5'-sulphatophosphate is an intermediate in the incorporation of sulphur from sulphate into cystine/cysteine in spinach leaf tissue.
Abstract: 1. An F−-insensitive 3′-nucleotidase was purified from spinach leaf tissue; the enzyme hydrolysed 3′-AMP, 3′-CMP and adenosine 3′-phosphate 5′-sulphatophosphate but not adenosine 5′-nucleotides nor PPi. The pH optimum of the enzyme was 7.5; Km (3′-AMP) was approx. 0.8mm and Km (3′-CMP) was approx. 3.3mm. 3′-Nucleotidase activity was not associated with chloroplasts. Purified Mg2+-dependent pyrophosphatase, free from F−-insensitive 3′-nucleotidase, catalysed some hydrolysis of 3′-AMP; this activity was F−-sensitive. 2. Adenosine 5′-sulphatophosphate kinase activity was demonstrated in crude spinach extracts supplied with 3′-AMP by the synthesis of the sulphate ester of 2-naphthol in the presence of purified phenol sulphotransferase; purified ATP sulphurylase and pyrophosphatase were also added to synthesize adenosine 5′-sulphatophosphate. Adenosine 5′-sulphatophosphate kinase activity was associated with chloroplasts and was released by sonication. 3. Isolated chloroplasts synthesized adenosine 3′-phosphate 5′-sulphatophosphate from sulphate and ATP in the presence of a 3′-nucleotide; the formation of adenosine 5′-sulphatophosphate was negligible. In the absence of a 3′-nucleotide the synthesis of adenosine 3′-phosphate 5′-sulphatophosphate was negligible, but the formation of adenosine 5′-sulphatophosphate was readily detected. Some properties of the synthesis of adenosine 3′-phosphate 5′-sulphatophosphate by isolated chloroplasts are described. 4. Adenosine 3′-phosphate 5′-sulphatophosphate, synthesized by isolated chloroplasts, was characterized by specific enzyme methods, electrophoresis and i.r. spectrophotometry. 5. Isolated chloroplasts catalysed the incorporation of sulphur from sulphate into cystine/cysteine; the incorporation was enhanced by 3′-AMP and l-serine. It was concluded that adenosine 3′-phosphate 5′-sulphatophosphate is an intermediate in the incorporation of sulphur from sulphate into cystine/cysteine.

Journal ArticleDOI
TL;DR: In this article, the binding energies of the outer electronic bands of the alkali fluorides were determined using 40.81 eV ultraviolet photoelectron spectroscopy, and an approximate difference of 1.1(1)eV between experimental and Born model binding energies was attributed to polarization effects.

Journal ArticleDOI
TL;DR: Mutants of Aspergillus nidulans with lesions in gene amdT are pleiotropically affected in their ability to utilize a wide variety of nitrogen sources in the presence of glucose, with properties consistent with it being derepressed for glucose repression of the utilization of most (but not all) nitrogen sources.
Abstract: Mutants of Aspergillus nidulans with lesions in gene amdT are pleiotropically affected in their ability to utilize a wide variety of nitrogen sources in the presence of glucose. Ability to utilize a number of these compounds as sole sources of carbon and nitrogen is not altered. One of these mutants, amdT102, has properties consistent with it being derepressed for glucose repression of the utilization of most (but not all) nitrogen sources. The amdT102 mutant can grow strongly on histidine, lysine and cystine as sole nitrogen sources while the wild type strain grows extremely poorly on these amino acids. Similar but less extreme effects apply to many other nitrogen sources. The amdT19 mutant is unable to utilize most nitrogen sources in the presence of glucose, suggesting that it is subject to greatly increased repression of nitrogen source utilization. The amdT mutants are not affected in their ability to use many compounds as sole carbon sources. Carbon sources other than glucose also affect utilization of nitrogen sources in the amdT mutants.

Journal ArticleDOI
TL;DR: It appears that DNA polymerase I plays an important role in cellular recovery from PD treatment, and it is suggested that the recombinational repair process is less important for Recovery from PD than for recovery from UV, and that the primary contribution of the rec genes to recovery fromPD may be in repair of single-strand gaps by repair resynthesis.
Abstract: The effect of acridine orange (AO)-sensitized photodynamic treatment (PD) was studied in various repair-deficient mutants of Salmonella typhimurium and Escherichia coli. Bacteria of either species carrying mutations in the polA gene and hence deficient in the enzyme DNA polymerase I were significantly more sensitive to PD-killing than polA + parent bacteria or phenotypically POL+ revertants of the polA strains (selected on the basis of resistance to methyl methanesulphonate). It therefore appears that DNA polymerase I plays an important role in cellular recovery from PD treatment. E. coli carrying a mutation in the recA gene was also more sensitive to PD-treatment than its parent strain, as was S. typhimurium carrying a mutation of the recA type. In S. typhimurium the rec mutant was somewhat less sensitive to PD-killing than the pol mutant even although it is much more sensitive to ultraviolet killing. E. coli strains with mutations in the recB and recC genes were intermediate in PD sensitivity between the recA and the parent strain. S. typhimurium and E. coli bacteria with mutations in the polA and recA genes showed reduced ability to host-cell reactivate PD-damaged bacteriophages ES 18 and λc1, indicating that the polA + and recA + gene products also contribute to repair of bacteriophages damaged by PD treatment. It is suggested that the recombinational repair process is less important for recovery from PD than for recovery from UV, and that the primary contribution of the rec genes to recovery from PD may be in repair of single-strand gaps by repair resynthesis.


Journal ArticleDOI
TL;DR: Data from studies using direct chemical stimulation of the rat brain to investigate eating and drinking behavior have given rise to the hypothesis of chemically coded neural control or behavior circuits, often in close spatial, anatomical proximity.
Abstract: Data from studies using direct chemical stimulation of the rat brain to investigate eating and drinking behavior have given rise to the hypothesis of chemically coded neural control or behavior circuits, often in close spatial, anatomical proximity. These studies and others are reviewed. The questions of the anatomical and chemical specificity of direct stimulation of the brain, and the relationship between chemically elicited behavior and deprivation induced behavior is examined.

Journal ArticleDOI
TL;DR: By carefully controlling the conditions of dark incubation, the photosynthetic capacity can be reduced to a very low level without significantly affecting chlorophyll a concentration, and it is possible to study aspects of chloroplast development without the complication of an associated synthesis ofchlorophyll.
Abstract: The light-saturated photosynthetic capacity of cultures of Phaeodactylum tricornutum Bohlin grown under different conditions has been measured. In batch cultures grown in a regime of alternating light and dark periods, the photosynthetic capacity reaches a maximum before the end of the exponential phase of growth, and declines thereafter. In cultures illuminated at 0.7 mW (milliwatt)/cm2, there is a 75% falloff in photosynthetic capacity per cell over an 8 day period following the time of maximum photosynthetic capacity. At 1.75 mW/cm2, the corresponding fall-off is 85% over a 4 day period. Cultures exposed to a prolonged period of darkness (up to 16 days at 18°C) maintain a high photosynthetic capacity. Incubation in darkness also protects the cells from the deleterious effects of high temperature (28°C) upon photosynthetic capacity. The various fluctuations of photosynthetic capacity occur without any accompanying major changes in the concentration of chlorophyll a. Evidence from estimations of total protein and of the gross pattern of photosynthetic assimilation under different conditions suggests that the changes in photosynthetic capacity are largely controlled by the enzymic component of the photosynthetic machinery. By carefully controlling the conditions of dark incubation, the photosynthetic capacity can be reduced to a very low level without significantly affecting chlorophyll a concentration. Since the effect on photosynthetic capacity is reversible, it is possible to study aspects of chloroplast development without the complication of an associated synthesis of chlorophyll.

Journal ArticleDOI
TL;DR: In this article, it was shown that a linear fractional program can have a fractional linear program as its dual, under certain restrictions, under the assumption that the program is linear.

Journal ArticleDOI
10 Oct 1973-Genetica
TL;DR: Self-compatibility in Brassica campestris c.v. Arlo was ascribed to the segregation of a polygenic complex which is capable of modifying the incompatibility reaction to the point of self-fertility, or to a reduction in the strength of the reaction due to the presence of S alleles low in the dominance series.
Abstract: Self-incompatibility in Brassica campestris c.v. Arlo is controlled by a single locus sporophytic system. The identity and expression of the S alleles were determined in eight inbred and two hybrid families. It was found that co-dominance of alleles is more frequent in the stigma, whereas dominance relations between pairs of alleles predominate in the pollen. A linear order of dominance was established between six S alleles and alleles high, intermediate and low in the dominance series were recognized. In considering the variation in the expression of compatibility and the segregation ratios in inbred, F1, F2 and backcross progenies, the presence of a specific S allele conditioning self-fertility, or a single dominant self-compatibility factor independent of the S locus could not be established. Instead, self-compatibility in this cultivar was ascribed to the segregation of a polygenic complex which is capable of modifying the incompatibility reaction to the point of self-fertility, or to a reduction in the strength of the reaction due to the presence of S alleles low in the dominance series.

Journal ArticleDOI
TL;DR: In this paper, a representative selection of substituted benzonitriles was used to measure the frequency and intensities of the carbon tetrachloride solvent in the vCN mode.

Journal ArticleDOI
TL;DR: Spontaneous neoplasms—thoracic fibrosarcomata, a cerebellar medulloblastoma, two examples of pulmonary adenomatosis and four examples of lymphocytic neoplasia— were found in a routine histopathological study of 168 dasyurid marsupials whose reproductive biology was being studied at La Trobe University, Victoria, Australia.

Journal ArticleDOI
02 Jun 1973-Genetica
TL;DR: Evidence of the operation of some polygenic modifying complex was provided by an analysis of a diallel cross among seven of the inbred lines, which detected significant additive genetic variation among the parental lines, considerable non-allelic interaction and some dominance of an ambi-directional type.
Abstract: Continuous variation in the expression of self-incompatibility, from complete self-incompatibility to self-compatibility, was observed among plants of the spring turnip rape cultivar Arlo. Significance of the variation between inbred progenies of plants from the base population suggested that a polygenic system had some influence on the expression of self-compatibility. The responses to one generation of selection within some of these progenies supported this conclusion. Further evidence of the operation of some polygenic modifying complex was provided by an analysis of a diallel cross among seven of the inbred lines. The analysis detected significant additive genetic variation among the parental lines, considerable non-allelic interaction and some dominance of an ambi-directional type.

Journal ArticleDOI
TL;DR: There is a biochemical link involving a sodium pump and the transport of amino acids, between nerve impulse activity and neuronal protein synthesis, and this link may also interconvert short-term and long-term storage of memory.
Abstract: In vitro effects of the antibiotics - cycloheximide, puromycin and chloramphenicol, and the sodium pump blockers - ouabain, lithium and copper, on protein synthesis in the crude mitochondrial, postmitochondrial and synaptosomal fractions of chicken forebrain were studied. In the synaptosomal fraction there was a correlation between the inhibitions produced by the sodium pump blockers, of Na+/K+ ATPase activity, 14C-leucine uptake and the incorporation of 14C-leucine into protein; whereas the antibiotics only inhibited leucine incorporation into protein. The effects of these drugs on the in vivo incorporation of 14C-leucine into protein in various fractions of chicken forebrain were also studied. The results suggest that there is a biochemical link involving a sodium pump and the transport of amino acids, between nerve impulse activity and neuronal protein synthesis. This link may also interconvert short-term and long-term storage of memory.

Journal ArticleDOI
TL;DR: In this paper, the electron impact induced ionization and dissociation of NH 3 and PH 3 have been studied using a quadrupole mass spectrometer using deconvoluted first differential ionization efficiency curves.

Journal ArticleDOI
TL;DR: The Malpighian tubules of cercopoid larvae are anatomically differentiated and have an ultrastructure which is typical of cells synthesizing and exporting protein.

Journal ArticleDOI
TL;DR: In this article, eleven palladium(II) alkylxanthates have been prepared and their thermal properties investigated by thermogravimetric analysis and a thermal decomposition mechanism is proposed.

Journal ArticleDOI
TL;DR: In this paper, the electron impact induced ionization and dissociation of H 2 O and H 2 S have been studied using a quadrupole mass spectrometer and deconvoluted first differential ionization efficiency curves are presented.