Showing papers by "RMIT University published in 1982"

Obtaining the specific contact resistance from transmission line model measurements

Abstract: In characterizing ohmic contacts using the transmission line model, it is necessary to make a measurement referred to as the contact end resistance, as a result of modification to the sheet resistance under the contact. In this article we show that this contact end resistance and the consequent specific contact resistance can be deduced from simple resistance measurements carried out between contacts on a standard, transmission line model test pattern.

Mechanism of Inhibitory Effect of Unavailable Carbohydrate on Intestinal Calcium Absorption

Abstract: The effect of unavailable carbohydrates on the intestinal absorption of calcium was studied in rats raised for 7 or 8 weeks on diets containing 10 or 20% of cellulose, glucomannan, or pullulan. The following results were obtained a) Body weight gain was diminished more severely in glucomannan groups than in cellulose groups. b) Serum calcium levels were slightly lower in all groups fed unavailable carbohydrates, whereas serum inorganic phosphorus levels were similar to that of the control group. c) There was a significant reduction of bone ash from rats fed glucommanan or cellulose with 620 glycoside bonds. d) Calcium transport measured in the everted duodenal sac remarkable decreased in the glucomannan 20% group, but slightly increased in the cellulose groups. e) Calcium binding activity was lowered significantly in all groups fed unavailable carbohydrates. f) Alkaline phosphatase and sucrase activities in the duodenum were also markedly decreased by prolonged intake of unavailable carbohydrates. These results indicate that inhibitory effect of unavailable carbohydrates on intestinal calcium absorption is partially due to the loss of calcium binding protein caused by gastrointestinal transit of large amounts of undigested substances.

Gm allotypes and multiple sclerosis.

Abstract: SUMMARY Immnoglobulin allotypes (Gm) were analysed in 40 multiple sclerois (MS) patients and the distribution of phenotypes compared to that in 1220 healthy controls. The frequencies of Gm(1) and Gm(1, 2) are significantly increased in the patietns suggesting that the presence of the Gm3;5,13,14 haplotype confers a resistance to the development of MS.

Physical adsorption of gases at high pressure

Abstract: The grand canonical ensemble Monte Carlo method is used to simulate the behaviour of a marginally supercritical Lennard-Jones gas near a graphite surface. The results reproduce the cusp-like shape of the experimentally observed adsorption isotherms. Even at these high temperatures, the computations clearly show the occurrence of multilayer adsorption; up to four layers are discernible at sufficiently high pressures.

Inhibition of nitroblue tetrazolium reduction by metallothionein.

Abstract: Metallothionein inhibited in a concentration-dependent fashion the reduction of nitroblue tetrazolium [NBT] mediated by xanthine oxidase and by NADH-phenazine methosulfate. This catalytic activity of metallothionein for dismutation of O2- is dependent on the copper content in metallothionein.

Effect of sucrose and Acarbose feeding on the development of streptozotocin-induced diabetes in the rat.

Abstract: The effects of sucrose and Acarbose (alpha-glucosidase inhibitor) feeding on the development of diabetes were studied in streptozotocin-treated rats. Rats were raised on four different dietary regimens, viz, a sucrose diet (46% of the total weight in the form of sucrose, 24% as starch), a starch diet (70% as starch), a standard diet (laboratory chow: Oriental Yeast Co.) or an Acarbose diet (a standard diet containing 75 mg Acarbose/100g diet) for a week followed by an intraperitoneal injection of streptozotocin (70 mg/kg). Development of diabetes was determined by urinary and blood glucose levels (more than 250 mg/dl). The incidence of diabetes in the groups of rats fed on sucrose, starch, standard, and Acarbose diets was 100%, 80%, 70% and 47.6%, respectively. The development of diabetes was accelerated by sucrose feeding and depressed by Acarbose feeding. There was mild diabetes in rats fed on Acarbose diet. The sucrose feeding caused a marked increase of disaccharidase activities in the proximal part of the intestine and in the apical part of the villus-crypt gradient of epithelial cells. The Acarbose feeding caused a significant decrease of disaccharidase activities. The changes in protein content of the sucrase-isomaltase complex appeared to be in parallel with those of disaccharidase activities. These results suggest that intestinal disaccharidase activities are involved in the development of experimental diabetes induced by streptozotocin.

Contact resistance of polysilicon silicon interconnections

Abstract: Electrical contacts to poly are an important part of current silicon technology. In this letter we present a method of calculating the electrical characteristics for a planar poly to silicon contact. An interesting and significant result that is derived and discussed is a minimum contact resistance that is a strong function not only of the specific contact resistance of the contact interface but also of the contact geometry.

Library services to the off-campus and independent learner: a review of the literature

Abstract: This article is derived from the literature search for a minor thesis for an M. Lib. (Monash University, 1980). Whereas the thesis was concerned with library service to tertiary students taking courses by external study for academic awards, this article expands the literature review to include the adult independent learner. It outlines the problems of the off-campus and independent learner and attempts to review literature to 1981 of the UK, North America and Australasia concerning library services to this user group, together with relevant use studies. Additional topics included are library user education, and the expectations of academics concerning library use by their off-campus students.

Power Flow Outage Studies Using an Array Processor

Abstract: This paper describes the implementation of a fast solution technique for contingency analysis on an array processor connected to a host mainframe. This implementation employs a decoupled power-flow algorithm with reactive limits enforced by means of bus-type switching. By considering the vector properties of the solution technique, and using ready-made vector routines available for the array processor, a significant reduction in computation time has been achieved.

Comment on "Maxwell's equations in the multipolar representation"

Abstract: It is shown that Haller's interpretation of the unitary transformation from the minimalcoupling to the multipolar form of the Hamiltonian in nonrelativistic quantum electrodynamics not only conflicts with the Maxwell-Lorentz equations but also ascribes a special status to the minimal-coupling Hamiltonian which is not warranted by the general method of canonical quantization. The correct interpretation of the transformation as the quantum analog of a classical canonical transformation is reiterated. It is also shown that the transformation is equivalent to a gauge transformation of the electromagnetic potentials.

Transient Annealing of Ion Implanted Gallium Arsenide

Abstract: This paper provides a brief overview of the application of transient annealing to the removal of ion implantation damage and dopant activation in GaAs. It is shown that both the liquid phase and solid phase annealing processes are more complex in GaAs than those observed in Si. Particular attention is given to observations of damage removal, surface dissociation, dopant redistribution, solubility and the electrical properties of GaAs. The various annealing mechanisms are discussed and areas in need of further investigation are identified.

Factors Affecting the Ultraviolet-Initiated Polymerization of Vinyl Monomers

Abstract: Measurements of the extent of polymerization have been made for photoinitiated polymerization reactions using consistent conditions and a common monomer, butyl acrylate. Three radiation wavelengths were used and it was found that in most cases polymerization proceeded in the order 350 > 300 > 254 nm. From the range of photoinitiators studied it was found that those of the benzoin type, undergoing cleavage, promoted reaction faster than the benzophenone type, requiring a hydrogen abstraction mechanism. At 350 nm, those undergoing a cleavage mechanism showed reaction rates following the order of their ultraviolet absorption. A hydrogen donor such as a tertiary amine was necessary for the benzophenone-type initiators. Hydrogen donors tended to have mixed effects on polymerization produced by benzoin-type initiators. From a broad range of hydrogen donors used with benzophenone it was found that aliphatic tertiary amines were the most effective.

Calcium-binding proteins in bovine milk: Calcium-binding properties and amino acid composition

Abstract: The Ca2+-binding properties and amino acid compositions of two calcium-binding proteins (mCaBP-3 and mCaBP-4) purified fromff bovine milk were studied. mCaBP-3 was identified as a Cat +-bound type and mCaBP-4 as a Ca2+-free type by means of ion-exchange chromatog-raphy on a DEAE-5ephadex A-25 column. In polyacrylamide gel disc electrophoresis, both mCaBP-3 and mCaBP-4 had the same mobility of Rf=0.73 and the addition of 5 mM CaCl2 to the electrode buffer decreased the mobility from R f=0.73 to R f=0.49. mCaBP-3 and mCaBP-4 con-sisted of 120 and 122 amino acid residues, respectively. The molecular weights were 13, 758 and 13, 967, respectively. The amino acid com-positions of the two milk CaBPs very closely resembled each other. Both milk CaBPs were rich in aspartic acid, glutamic acid, leucine and lysine, but did not contain trimethylated lysine and amino sugar. An interesting feature is that each milk CaBP contained eight cysteine sulfone and three tryptophan residues per molecule. From these results, it is suggested thal mCaBP-3 and mCaBP-4 are identical protein and that mCaBP-3 is formed from mCaBP-4 by means of a conformational change by binding of Cat + Thus, mCaBP-3 is a holoprotein and mCaBP-4 is an apoprotein. Furthermore, it is suggested that milk CaBP is different from calmodulin, troponin C and vitamin D-dependent calcium-binding protein.

Decreased membrane fragility of mouse erythrocytes by small dose of methylmercury and its restoration by coadministered selenite.

Abstract: YAMAMOTO, R. and SUZUKI, T. Decreased Membrane Fragility of Mouse Erythrocytes by Small Dose of Methylmercury and Its Restoration by Coadministered Selenite. Tohoku J. exp. Med., 1982, 137 (3), 297-303-Female IVCS mice were fed methylmercury at a low dose level (10nmoles/g feed) with coadministration of selenite (0, 8, 20 or 50nmoles/ml of drinking water) for one week or two weeks. Mice fed methylmercury alone showed the decreased fragility of erythrocytes membrane when compared with the non-treated control. Coadministration of selenite produced such a change to smaller extents than methylmercury treatment alone. Mercury levels in the blood varied according to the dose level of selenite (the highest level was found in methylmercury alone group).

Urinary mercury excretion in the early phase of mercury vapor exposure in rabbits

Abstract: Rabbits were exposed to mercury vapor at concentrations from 0.03 to 10 mg Hg m−3 for 3 and 8 h. Mercury concentrations in urine, red blood cells and plasma, activities of several enzymes in urine, urinary protein and creatinine concentrations, and catalase activities in red blood cells were determined before and during the exposure. During latent periods for the detection of mercury after the start of exposure in urine, red blood cells or plasma showed an inverse correlation with the level of mercury in the inspired air. When the air mercury level was 1.5 mg Hg m−3 or below, mercury was not detected in plasma, in spite of a clear rise of urinary and erythrocytic mercury levels in the early time period during exposure. However, with air mercury higher than 2 mg Hg m−3, mercury was detected in urine, red blood cells and plasma. Urinary protein, urinary enzyme activities and blood catalase were unaffected during the course of exposure.

The Effect of Different Isolation Procedures on the Yields of Insulin-Like Growth Factors from Human Plasma

Abstract: Various procedures for the isolation of insulin-like growth factors(IGF's) from human plasma were evaluated with emphasis upon the yields of each species obtained. The procedures which were evaluated as first steps from plasma and mixed Cohn fractions included acid-ethanol extraction, heat coagulation, ion-exchange chromatography and gel filtration. Certain two-step combinations of these techniques were also evaluated in order to obtain higher fold-purification. Fractions obtained were tested initially using a competitive binding protein assay and then by radioimmuno assay(RIA) for IGF I and II. The results indicated that acceptable yields of IGF I and II were obtained by initial gel filtration of acidified plasma on Sephadex G-75 at pH 2.5 followed by chromatography on S.P. Sephadex C-25. Isoelectric focusing of the active fraction thereby obtained under these conditions and subsequent R.I.A. indicated total recoveries of IGF I and II of about 23 and 96 mU/litre respectively. Peak recoveries of ...

A survey of process hygiene in the Sri Lanka prawn industry

Abstract: A survey of process hygiene in the Sri Lanka prawn industry has shown that incoming raw materials had extremely high bacterial loadings, about 50% of samples analysed having total counts in excess of 107 g−1. Although deheading, washing and freezing reduced this loading, total bacterial counts on final products were often in the range 106-107 g−1. Staphyloccocus aureus often exceeded 102 g−1 though most samples had levels of Escherichia coli of < 6 g−1. Of 262 personnel in export prawn plants in Sri Lanka, 137 (52%) were found to carry S. aureus on their fingers; between companies the prevalence of S. aureus ranged from 22–92%. Although five companies provided sanitiser hand-dips this was found to be ineffective for the control of S. aureus. In addition, provision of hand-washing facilities, protective clothing and toilet facilities was inadequate. Of the 15 export plants surveyed, only five were found to have a process which was adequately controlled. The most common process defects included inadequate chilling of prawns following the several washing stages, use of block ice to chill prawns, high prawn:ice ratios, and cross contamination between processed and raw products.

Winter Leaf Spot on Borage Caused by Nigrospora oryzae

Abstract: dustries. Leaf samples were examined by us at Indooroopilly. The results of the surveys in the Torres Strait and northern Cape York Peninsula are presented in Figure 1. Black Sigatoka was detected on Murray, Badu, Moa and Thursday Islands in the Torres Strait and in the Bamaga area on the mainland. Freckle was more widespread and in addition to the above locat ions was recorded on Darnley, Stephen , Boigu , Saibai , Mabu iag and Hammond Islands in the Torres Strait and at Lockhart River on the east coast of Cape York Peninsula. Wind dispersal of ascospores may have been responsIble for the spread of black Sigatoka .and freckle from Papua New Guinea to islands in the Torres Strait and to northern areas of Cape York Peninsula. An alternative explanation is that the diseases were introduced by man . Fru it and planting material, wh ich could have had associated leaf trash, are known to have been moved in the past from Papua New Guinea to islands in the Torres Strait. Close ties between people in the islands and the Bamaga area have undoubtedly led to the movement of plantain or banana sword suckers and fruit to the mainland. The fungi could also have been disseminated on banana leaves, which are sometimes used by islanders to wrap food on journeys. The absence of black Sigatoka south of Bamaga could be attributed to its recent introduction to the region. However , the disease may have been present for some time, the natural barrier of bush in Cape York Peninsula preventing further spread. It has been suggested that the dissemination of black Sigatoka by windblown ascospores from small areas of infection to new areas may be restr icted if distances exceed 50 km (7). Distances between the isolated aborig inal .communities and cattle stat ions on Cape York Peninsula, most having only small stands of bananas, are usually more than 50 krn, In add ition, preva iling north west winds in the wet season may blow ascospores, which would be released at this time, off the coast. Lack of cultural ties between the island people at Bamaga and aborigines in the rest of Cape York Peninsula would have restricted the movement south of planting material and fruit. The presence of freckle at Lockhart River is a little pUZZling especially as the disease Is not found at Heathlands cattle station, Moreton Telecom Station or Weipa (see Figure 1). Although the dist ribution of banana types on most of Cape York Peninsula indicates a movement of plant ing material from the south , a transfer of planting material from Bamaga to Lockhart River may have occurred under the auspices of the Queensland Department of Aboriginal and Islanders Advancement. It is possible that ascospores may have been carried down the coast by cyclonic winds, but bananas in a few back gardens at Lockhart River would have presented a very small target. The role that native bananas found in pockets of rain forest on the east coast of Cape York Peninsula would play in the dissemination of the disease is unknown. However, Musa banksii F. Muell. has been recorded as a host of M. musicale (5) and therefore may be susceptible to M. tiiiensis var. difformis. An attempt is being made to eradicate black Sigatoka and freckle from mainland Australia because there is a danger that the diseases may spread to a banana olantation at Weipa South and later to commercial growing areas in north Queensland. All bananas in the Bamaga area and in back gardens at the Lockhart River settlement have been destroyed. After a suitable host-free period, clean planting material is t, be introduced from the south. It has