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Showing papers by "Australian National University published in 1988"


Journal ArticleDOI
TL;DR: In this paper, the authors examined bias in dynamic models with fixed effects where both the number of time series observations and cross-sectional replications are small, and the formula bias estimate was in line with that in published Monte Carlo studies.

3,345 citations


Journal ArticleDOI
TL;DR: In this paper, the relations between colors of the JHKL systems of several observatories are examined, and linear relations are derived for transformation between the (J-K), (H, K, H, and L) colors in the different systems.
Abstract: The relations between colors of the JHKL systems of several observatories are examined, and linear relations are derived for transformation between the (J-K), (J-H), (H-K), and (K-L) colors in the different systems. A homogenized system is proposed, based on the systems of Glass (1984) and Johnson et al. (1966). The homogenized data sets are used to derive intrinsic colors for a number of giants and dwarfs. The passbands of several IR systems are estimated and the synthetic colors of the systems are compared using blackbody and stellar fluxes. The passbands were adjusted in wavelength to produce agreement with observed relations between different systems, making it possible to estimate the effective wavelengths of the different natural systems.

2,213 citations


Book
01 Jan 1988
TL;DR: In this paper, the authors discuss the development of a rather complete inferential theory for ARMAX models and discuss the asymptotic properties of these estimators without assuming the data to be Gaussian and also discuss the basis of the assumptions that appear to be minimal.
Abstract: Publisher Summary The chapter discusses the development of a rather complete inferential theory for ARMAX models. The first problem in the development is the coordinatization of spaces of such structures. Coordinates are needed both for computations and because a central limit theorem must be expressed in terms of them. One such coordinatization would follow from the use of the coefficient matrices in g, h, j in the scalar m.f.d., but there are many others. The chapter highlights the algebraic and topological description of ARMAX systems. In this connection, control engineers have played a premier part. The chapter focuses on the asymptotic properties of maximum likelihood (ML) estimators. The ML estimator is obtained by optimizing this likelihood. The chapter explains the asymptotic properties of these estimators without assuming the data to be Gaussian and also discusses the basis of the assumptions that appear to be minimal.

940 citations



Journal ArticleDOI
TL;DR: Analyse statistique de la fonction de luminosite des galaxies de champ de plusieurs catalogues is presented in this paper ; les different methods d'estimation sont testees.
Abstract: Analyse statistique de la fonction de luminosite des galaxies de champ de plusieurs catalogues. Les differentes methodes d'estimation sont testees. On montre que la fonction de luminosite de champ peut etre decrite par une fonction de Schechter dont on calcule les differents parametres

581 citations


Journal ArticleDOI
TL;DR: The static spherically symmetric Einstein-Yang-Mills equations with SU(2) gauge group are studied and numerical solutions which are nonsingular and asymptotically flat are found.
Abstract: We study the static spherically symmetric Einstein-Yang-Mills equations with SU(2) gauge group and find numerical solutions which are nonsingular and asymptotically flat. These solutions have a high-density interior region with sharp boundary, a near-field region where the metric is approximately Reissner-N\o{}rdstrom with Dirac monopole curvature source, and a far-field region where the metric is approximately Schwarzschild.

570 citations


Journal ArticleDOI
TL;DR: A model for interdependent demand for health insurance and health care under uncertainty is developed to throw light on the issue of insurance-induced distortions in thedemand for health care services.
Abstract: This paper develops a model for interdependent demand for health insurance and health care under uncertainty to throw light on the issue of insurance-induced distortions in the demand for health care services. The model is used to empirically analyse the determinants of the choice of health insurance type and seven types of health care services using micro-level data from the 1977–78 Australian Health Survey. Econometric implementation of the model involves, simultaneously, issues of discreteness of choice, selectivity and stochastic dependence between health insurance and utilization. Health status appears to be more important in determining health care service use than health insurance choice, while income appears to be more important in determining health insurance choice than in determining health care service use. For a broad range of health care services both moral hazard and self selection are found to be important determinants of utilization of health care services.

523 citations


Journal ArticleDOI
TL;DR: In this article, an adaptive observer/identifier for single input/single output observable nonlinear systems that can be transformed to a certain observable canonical form is described, and sufficient conditions for stability of this observer are provided.
Abstract: An adaptive observer/identifier for single input/single output observable nonlinear systems that can be transformed to a certain observable canonical form is described. Sufficient conditions for stability of this observer are provided. These conditions are in terms of the structure of the system and canonical form, the boundedness of the parameter variations, and the sufficient richness of some signals. The scope of the canonical form and the use of the observer/identifier is motivated by the presentation of applications to time-invariant bilinear systems, nonlinear systems in phase-variable form a biotechnological process, and a robot manipulator. In each case, the specific stability conditions are presented. >

501 citations


Journal ArticleDOI
TL;DR: Data surveillance is now supplanting conventional surveillance techniques as discussed by the authors and with this trend come new monitoring methods such as personal data surveillance and mass data surveillance that require more effective safeguards and a formal policy framework.
Abstract: Data surveillance is now supplanting conventional surveillance techniques. With this trend come new monitoring methods such as personal dataveillance and mass dataveillance that require more effective safeguards and a formal policy framework.

493 citations


Journal ArticleDOI
TL;DR: It is estimated that the ratio of internal to external partial pressure of CO2 in Leaves of high elevation plants is lower than in leaves of low altitude, which indicates decreasing relative limitation of carbon uptake by carboxylation.
Abstract: Carbon 13/12 isotope ratios have been determined from leaves of a hundred C3 plant species (or ecotypes) from all major mountain ranges of the globe, avoiding drought stressed areas. A general increase in 13C content was found with increasing altitude, i.e. overall discrimination against the heavy isotope is reduced at high elevation. The steepest decline of discrimination is observed in taxa typically ranging to highest elevations (e.g. the genus Ranunculus). Mean δ 13C for all samples collected between 2500 and 5600 m altitude is-26.15‰ compared to the lowland average of-28.80‰ (P<0.001). Forbs from highest elevations reach-24‰. According to theory of 13C discrimination this indicates decreasing relative limitation of carbon uptake by carboxylation. In other words, we estimate that the ratio of internal to external partial pressure of CO2 (p i /p a )in leaves of high elevation plants is lower than in leaves of low altitude. These results confirm recent gas exchange analyses in high and low elevation plants.

489 citations


Journal ArticleDOI
TL;DR: In this paper, a functional understanding of the physical and biological processes underlying mangrove ecosystem dynamics is presented. But this process is not suitable for the management of mangroves.
Abstract: Mangrove forests are of major ecological and commercial importance, yet the future of these resources is threatened by pollution, development and over-exploitation. There is an urgent need to develop sound management practices based on a functional understanding of the physical and biological processes underlying mangrove ecosystem dynamics. Such biological processes include dispersal (Rabinowitz 1978), herbivory (Smith 1987) and the physiological bases of species interactions and responses to environmental factors. Understanding these processes is essential for the development of more comprehensive and predictive modelling of mangrove ecosystem dynamics than has previously been possible.

Journal ArticleDOI
TL;DR: Geochemical and isotopic data for 13 carbonatites from Africa, Australia, Brazil, Europe and the United States have been reported in this paper, with a range of initial Ba, Th, LREE, Sr and low Cs, Rb, K and HREE abundances.

Journal ArticleDOI
TL;DR: In this paper, the problem of smoothing parameter selection for nonparametric curve estimators in the specific context of kernel regression estimation is addressed, and the convergence rate turns out to be excruciatingly slow.
Abstract: We address the problem of smoothing parameter selection for nonparametric curve estimators in the specific context of kernel regression estimation. Call the “optimal bandwidth” the minimizer of the average squared error. We consider several automatically selected bandwidths that approximate the optimum. How far are the automatically selected bandwidths from the optimum? The answer is studied theoretically and through simulations. The theoretical results include a central limit theorem that quantifies the convergence rate and gives the differences asymptotic distribution. The convergence rate turns out to be excruciatingly slow. This is not too disappointing, because this rate is of the same order as the convergence rate of the difference between the minimizers of the average squared error and the mean average squared error. In some simulations by John Rice, the selectors considered here performed quite differently from each other. We anticipated that these differences would be reflected in differ...

Journal ArticleDOI
TL;DR: The Tait equation as discussed by the authors is a modification of the original equation of Tait, published 100 years ago, to fit his results on the compressibility of fresh water and seawater at different pressures.
Abstract: The “Tait equation,” which is now widely used to fit liquid density data over wide pressure ranges, is a modification of the original equation of Tait, published 100 years ago, to fit his results on the compressibility of fresh water and seawater at different pressures. The range of applicability of these different equations is discussed and it is concluded that their simplicity and accuracy in reproducing high pressure density data for dense gases, liquids, solids, and liquid mixtures will ensure their continued use.

Journal ArticleDOI
TL;DR: In this article, it was suggested that thermal evolution of the region, involving a delayed convective instability of the base of the thickened lithosphere, could have raised the surface elevation and the potential energy of the Tibetan Plateau, leading to the observed extension there.
Abstract: Continental convergence results in compressional deformation over a distance, perpendicular to strike, that is comparable to the length of the convergent boundary. The compressional forces generated by the convergence are resisted, to some extent, by the extensional deviatoric stresses arising from isostatically balanced increases in crustal thickness; as a result a plateau may form, in front of a compressional boundary, whose elevation is limited by the strength of the continental lithosphere. However, the extensional stresses do not exceed the compressional stresses that generate the crustal-thickness contrasts unless there is a major change, either in the convergent velocity or in the potential energy of the elevated region. For the collision of India with Asia, it appears that there has not been a change in the convergent boundary condition sufficient to cause the late-Tertiary to present extension in the region. It is suggested that thermal evolution of the region, involving a delayed convective instability of the base of the thickened lithosphere, could have raised the surface elevation and the potential energy of the Tibetan Plateau, leading to the observed extension there.

Journal ArticleDOI
TL;DR: Results indicate that the apparent non-stomatal inhibition of photosynthesis by ABA deduced from the depression of A(Pi) relationship is an artifact which can be attributed to the non-uniform distribution of transpiration and photosynthesis over the leaf.
Abstract: The effects of abscisic acid (ABA) on photosynthesis in leaves of Helianthusannuus L. were compared with those in leaves of Viciafaba L. After the ABA treatment, the response of photo­ synthetic CO2 assimilation rate, A, to calculated intercellular partial pressure of CO2 , Pi' (A(Pi) relationship) was markedly depressed in H. annuus. A less marked depression was also observed in Vifaba. However, when the abaxial epidermes were removed from these leaves, neither the maximum rate nor the CO 2 response of photosynthetic oxygen evolution was affected by the ap­ plication of ABA. Starch-iodine tests revealed that photosynthesis was not uniform over the leaves of H. an­ nuus treated with ABA. The starch content was diffferent in each bundle sheath extension com­ partment (the smallest subdivision of mesophyll by veins with bundle sheath extensions, hav­ ing an area of ca. 0.25 mrrr' and ca. 50 stomata). In some compartments, no starch was detected. The distribution of open stomata, examined using the silicone' rubber impression tech­ niques, was similar to the pattern of starch accumulation. In Vifaba leaves, which lack bundle sheath extensions, distribution of starch was more homogeneous. These results indicate that the apparent non-stomatal inhibition of photosynthesis by ABA deduced from the depression of A(Pi) relationship is an artifact which can be attributed to the non-uniform distribution of transpiration and photosynthesis over the leaf. Intercellular gaseous environment in the ABA-treated leaves is discussed in relation to mesophyll anatomy.

Journal ArticleDOI
22 Jan 1988-Science
TL;DR: The interaction in water of neutral hydrocarbon and fluorocarbon surfaces, prepared by Langmuir-Blodgett deposition of surfactant monolayers, has been investigated and the attraction between these hydrophobic surfaces can be measured at separations of 70 to 90 nanometers and thus is of considerably greater range than previously found.
Abstract: The interaction in water of neutral hydrocarbon and fluorocarbon surfaces, prepared by Langmuir-Blodgett deposition of surfactant monolayers, has been investigated. The attraction between these hydrophobic surfaces can be measured at separations of 70 to 90 nanometers and thus is of considerably greater range than previously found. Spontaneous cavitation occurred as soon as the fluorocarbon surfaces were brought into contact but occurred between the hydrocarbon surfaces only after separation from contact. The very long range forces measured are a consequence of the metastability of water films between macroscopic hydrophobic surfaces. Thus the hydrophobic interaction between macroscopic surfaces may not be related to water structure in the same way that the hydrophobic effect between nonpolar molecules is related to water structure.

Journal ArticleDOI
TL;DR: In this paper, the authors construct a simple but fairly general model of household resource allocation and use the properties of the equilibrium of this model to characterise the effects of tax policy on individual utilities.

Journal ArticleDOI
TL;DR: In this paper, the star-triangle relations for a nearest-neighbour two-spin interaction model are given in terms of two rapidities associated with two lines, which cross through each edge.

Journal ArticleDOI
01 Jul 1988-Ethics
TL;DR: In this article, it was shown that at least some of our general duties to those beyond our borders are at least sometimes more compelling, morally speaking, than at leastsome of our special duties to our own compatriots.
Abstract: There are some "general duties" that we have toward other people, merely because they are people. Over and above those, there are also some "special duties" that we have toward particular individuals because they stand in some special relation to us. Among those are standardly supposed to be special duties toward our families, our friends, our pupils, our patients. Also among them are standardly supposed to be special duties toward our fellow countrymen. Where those special duties come from and how they fit with the rest of morality is a moot point. I shall say little about such foundational issues, at least at the outset. In my view, the best way of exploring foundations is by examining carefully the edifice built upon them. The bit of the edifice that I find particularly revealing is this: When reflecting upon what "special treatment" is due to those who stand in any of these special relations to us, ordinarily we imagine that to be especially good treatment. Close inspection of the case of compatriots reveals that that is not completely true, however. At least in some respects, we are obliged to be more scrupulous-not less-in our treatment of nonnationals than we are in our treatment of our own compatriots.' This in itself is a politically important result. It shows that at least some of our general duties to those beyond our borders are at least sometimes more compelling, morally speaking, than at least some of our special duties to our fellow citizens. This finding has the further effect of forcing us to reconsider the bases of our special duties to compatriots, with yet further political consequences. Morally, what ultimately matters is not nationality per se. It is instead some further feature that is only contingently and imperfectly associated with shared nationality. This further feature may sometimes

Journal ArticleDOI
TL;DR: In barbiturate-anaesthetized spinal cats, antibody microprobes were used to examine immunoreactive substance P (irSP) release at sites within the spinal cord following cutaneous stimuli, supporting a role for SP in the transmission of information from nociceptors to spinal neurones.

Journal ArticleDOI
TL;DR: Tables de donnees sur les etats electroniques excites et etude detaillee of ces etats (origine de l'observation, potentiel d'ionisation, structure vibrationnelle, constantes de rotation...) as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the best way to formulate and estimate a dynamic econometric model when interest focuses mainly upon its long-run properties, using results derived for the more general context of transformed regression models, and show how point estimates and the standard errors of long run multipliers and long run structural coefficients can be obtained using standard estimation methods.
Abstract: This paper discusses the best way to formulate and estimate a dynamic econometric model when interest focuses mainly upon its long-run properties. Using results derived for the more general context of transformed regression models, it is shown how point estimates and the standard errors of long-run multipliers and long-run structural coefficients can be obtained using standard estimation methods. It is argued that such formulations are preferable to other specifications such as the error correction model. If the explanatory variables that enter the long-run solution are trend-stationary then it is found that no harm is done to the asymptotic properties of the long-run coefficients by omitting short-run dynamics entirely, though this is not recommended in practice. The results of this paper are related to the concept of co-integration and to the work of Engle and Granger. Finally, a new methodology for the construction of dynamic models is proposed.

Journal ArticleDOI
TL;DR: The results suggest that nitrogen nutrition affects the amount of thyalkoids per unit leaf area but neither the properties of Thyalkoids nor their intra-leaf gradient, however, growth irradiance controls both the properties and the amounts of thylakoids.
Abstract: Nitrogen budgets of fully expanded young leaves of Spinacia oleracea L. grown under three growth irradiances at four nitrate concentrations, were compared in relation to photosynthesis. The proportion of nitrogen allocated to thylakoid membranes was 24% of total leaf nitrogen irrespective of the growth conditions. The composition of the photosynthetic components in thylakoid membranes was affected by growth irradiance but unaffected by nitrogen levels. The proportion of total leaf nitrogen allocated to soluble protein and RuBP carboxylase (RuBPCase) increased with the increases in nitrogen and in irradiance levels. Some ultrastructural properties of chloroplasts and their intra-leaf gradients were also compared. The results suggest that nitrogen nutrition affects the amount of thyalkoids per unit leaf area but neither the properties of thyalkoids nor their intra-leaf gradient. Growth irradiance, however, controls both the properties and the amount of thylakoids. The ratio of in vitro RuBPCase activity to electron transport/photophosphorylation activity increased with the increase in nitrogen level, but decreased with the increase in growth irradiance. The change in the ratio of in vitro activities may serve to balance the in vivo activities, given that the in vivo efficiency of RuBPCase declines with the increase in volume of a chloroplast due to the increased liquid phase resistance to CO 2 diffusion.

Journal ArticleDOI
TL;DR: In this paper, detrital zircon grains from Archaean quartzites from the Mweza and Shurugwi greenstone belts have been dated by the ion probe SHRIMP.
Abstract: 86 detrital zircon grains from Archaean quartzites from the Mweza and Shurugwi greenstone belts have been dated by the ion probe SHRIMP. Nine of these give ages of 3.75–3.80 Ga, older than any Zimbabwean rocks so far satisfactorily dated, and the Tokwe-Zvishavane gneisses are a possible source for these old grains. However, none are comparable in age with the 4.2 Ga zircons discovered in Western Australia. If such old grains exist in the sample it is unlikely (P>0.05) that their abundance could exceed 3%. Ages of the younger grains are broadly consistent with the presumed age of the quartzites sampled, though some high Th/U grains in the Shurugwi sample may be anomalously young.

Journal ArticleDOI
TL;DR: In this paper, an 18-parameter family of integrable reversible mappings of the plane is presented, which are shown to occur in soliton theory and in statistical mechanics.

Journal ArticleDOI
TL;DR: In this article, X-ray absorption edge spectra indicate the presence of tetrahedral Fe3+, a conclusion supported by heating experiments which show the development of maghemite after heating to 300°C, followed by the formation of hematite at higher temperatures.
Abstract: Synthetic 2-line and 6-line ferrihydrite samples prepared from ferric nitrate solutions have the bulk compositions Fe4(O,OH,H2O)12 and Fe4,6(O,OH,H2O)12, respectively. The composition depends on crystal size, which averages 20 A for 2-line and 35 A for 6-line ferrihydrite. X-ray absorption edge spectra indicate the presence of tetrahedral Fe3+, a conclusion supported by heating experiments which show the development of maghemite after heating to 300°C in the presence of N2, followed by the formation of hematite at higher temperatures. These two reactions are recorded on differential thermal analysis traces by exotherms at 350° and 450°C. Transmission electron microscopy shows that 2-line ferrihydrite has no Z-axis regularity but does show hexagonal 2.54-A lattice fringes. Six-line ferrihydrite forms faceted crystals having 9.4-A c-parameter only detectable in dark field. In bright field, 2.54-A lattice fringes indicate greater atomic regularity than in 2-line ferrihydrite. Analysis of the X-ray powder diffraction pattern of 6-line ferrihydrite suggests a structure based on double-hexagonal close-packed oxygens, containing 36% Fe in tetrahedral sites. Selective chemical dissolution, surface area measurements, and magnetic susceptibility are consistent with the recorded properties of ferrihydrite.

Journal ArticleDOI
TL;DR: Delta in starch and sugars suggests that carbon isotope analysis in leaf starch and soluble sugars may be used for monitoring, indirectly, the average of p(i)/p(a) weighted by CO(2) assimilation rate, over a day.
Abstract: Carbon isotope discrimination (Δ) was analyzed in leaf starch and soluble sugars, which represent most of the recently fixed carbon. Plants of three C3 species (Populus nigra L. × P. deltoides Marsh., Gossypium hirsutum L. and Phaseolus vulgaris L.) were kept in the dark for 24 hours to decrease contents of starch and sugar in leaves. Then gas exchange measurements were made with constant conditions for 8 hours, and subsequently starch and soluble sugars were extracted for analysis of carbon isotope composition. The ratio of intercellular, pi, and atmospheric, pa, partial pressures of CO2, was calculated from gas exchange measurements, integrated over time and weighted by assimilation rate, for comparison with the carbon isotope ratios in soluble sugars and starch. Carbon isotope discrimination in soluble sugars correlated strongly (r = 0.93) with pi/pa in all species, as did Δ in leaf starch (r = 0.84). Starch was found to contain significantly more 13C than soluble sugar, and possible explanations are discussed. The strong correlation found between Δ and pi/pa suggests that carbon isotope analysis in leaf starch and soluble sugars may be used for monitoring, indirectly, the average of pi/pa weighted by CO2 assimilation rate, over a day. Because pi/pa has a negative correlation with transpiration efficiency (mol CO2/mol H2O) of isolated plants, Δ in starch and sugars may be used to predict differences in this efficiency. This new method may be useful in ecophysiological studies and in selection for improved transpiration efficiency in breeding programs for C3 species.

Journal ArticleDOI
01 May 1988-Nature
TL;DR: The Antarctic ice sheets provided a significant contribution to the sea-level rise at a rate that was approximately synchronous with the melting of the Laurentide ice sheet, except for the interval 9,000-6,000 years ago, when it may have lagged behind as mentioned in this paper.
Abstract: Spatial and temporal variations in the sea levels of the past 20,000 years around the globe place constraints on the melting history of the major late Pleistocene ice sheets. The Antarctic ice sheets provided a significant contribution to the sea-level rise at a rate that was approximately synchronous with the melting of the Laurentide ice sheet, except for the interval 9,000–6,000 years ago, when it may have lagged behind. Minor melting of the Antarctic ice sheet continued throughout the Holocene

Journal ArticleDOI
01 Jan 1988-Nature
TL;DR: In this article, a hybrid convection model was proposed to explain the properties of the seismic discontinuity at 650km depth and the geochemical evolution of the upper and lower mantle.
Abstract: Chemical buoyancy relationships during subduction of young, thin oceanic plates cause them to be trapped in a gravitationally stable layer between 600 and 700 km that partly isolates the convective systems of the upper and lower mantle. But when mature, thick plates are subducted, their upper, cool differentiated layers may break through this barrier and become entrained in the convective circulation of the lower mantle. The resultant hybrid convection model provides a promising explanation of the properties of the seismic discontinuity at 650km depth and the geochemical evolution of the mantle.