http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12438 A relationship between cytotrophoblast differentiation (syncytialisation) and apoptosis is hypothesised to exist, but has not been clearly determined. To address this, we explored the effects of cAMP, an inducer of syncytialisation, on human choriocarcinoma cell differentiation and viability under three different culture conditions related to diverse survival status: no serum, 10% fetal calf serum or 10% charcoal-stripped fetal calf serum. 8-Br-cAMP increased BeWo cell viability in culture media without serum, but viability was decreased in a dose- and time-dependent manner when serum was present. The appearance of apoptotic nuclei fragments were only observed when BeWo cells were cultured in media containing serum combined with 8-Br-cAMP treatment. In addition, the ratio of FasL to Fas expression following treatment with 8-Br-cAMP increased by 20-fold in 10% charcoal-stripped fetal calf serum media and 65-fold 10% fetal calf serum media, and activation of caspase-3 also required media with serum. The markers of syncytialisation (syncytin 1 expression and human chorionic gonadotropin secretion) were induced significantly by 8-Br-cAMP, and were higher in 10% fetal calf serum media than in 10% charcoal-stripped fetal calf serum media, than in the absence of serum. Syncytia formation was stimulated by 8-Br-cAMP and this required serum in the media. We now show that factors contained within serum are necessary for cAMP-stimulated cytotrophoblast differentiation, that syncytialisation involves apoptotic events, and that a lack of serum based factors could switch the cellular program away from differentiation. 2013-01-16T05:20:03.781Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8163 We report erosion rates and processes, determined from in situ-produced beryllium-10 (¹⁰Be) and aluminum-26 (²⁶Al), across a soil-mantled landscape of Arnhem Land, northern Australia. Soil production rates peak under a soil thickness of about 35 cm and we observe no soil thicknesses between exposed bedrock and this thickness. These results thus quantify a well-defined ‘humped’ soil-production function, in contrast to functions reported for other landscapes. We compare this function to a previously reported exponential decline of soil production rates with increasing soil thickness across the passive margin exposed in the Bega Valley, south-eastern Australia, and found remarkable similarities in rates. The critical difference in this work was that the Arnhem Land landscapes were either bedrock or mantled with soils greater than about 35 cm deep, with peak soil production rates of about 20 m/Ma under 35–40 cm of soil, thus supporting previous theory and modeling results for a humped soil production function. We also show how coupling point-specific with catchment-averaged erosion rate measurements lead to a better understanding of landscape denudation. Specifically, we report a nested sampling scheme where we quantify average erosion rates from the first-order, upland catchments to the main, sixth-order channel of Tin Camp Creek. The low (~5 m/Ma) rates from the main channel sediments reflect contributions from the slowly eroding stony highlands, while the channels draining our study area reflect local soil production rates (~10 m/Ma off the rocky ridge; ~20 m/Ma from the soil mantled regions). Quantifying such rates and processes help determine spatial variations of soil thickness as well as helping to predict the sustainability of the Earth's soil resource under different erosional regimes. 2011-07-07T04:30:13.834Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2248 This paper presents a numerical formulation for frictional contact problems associated with pile penetration. The frictional contact at the soil–pile interface is formulated using the theory of hardening/softening plasticity, so that advanced models for the interface can be dealt with. A smooth discretisation of the pile surface is proposed using BéZIER polynomials. An automatic load stepping scheme is proposed,which features an error control algorithm and automatic subincrementation of the load increments. The numerical algorithms are then used to analyse the installation process of pushed-in axial piles. It is shown that the smooth discretisation of the pile surface is effective in reducing the oscillation in the predicted pile resistances and the automatic load stepping scheme outperforms the classical Newton–Raphson scheme for this type of problem. 2010-04-27T06:56:55.046Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3249 An IC-MRCI ansatz was employed with hydrogen and helium [5s,4p,3d,2f] and beryllium [9s,8p,6d,4f,2g] single-particle basis sets to characterise the ground electronic states of BeH2, HBeHe⁺ and BeHe²₂⁺. CCSD(T) and IC-MRCI equilibrium structures for both these molecules are in excellent agreement with predicted trends in terms of geometry, vibrational frequencies and potential well depths. Discrete IC-MRCI potential energy surfaces consisting of 89 and 87 points were constructed for the HBeHe⁺ and BeHe²₂⁺ ground states, respectively. Padé approximants were employed to construct analytical representations of the surfaces of HBeHe⁺ and BeHe²₂⁺, yielding (χ2)1/2 values of 64.2 and 31.4 μEh, respectively. 2010-04-27T05:24:05.161Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3250 UCCSD(T) and IC-MRCI methods have been employed in conjunction with large contracted basis sets for He [5s, 4p, 3d, 2f] and Be [9s, 8p, 6d, 4f, 2g] to characterize the ground electronic state of BeHe⁺₂. For both UCCSD(T) and IC-MRCI wave functions, basis set superposition errors were included, with size-extensivity corrections included for IC-MRCI calculations. UCCSD(T) and IC-MRCI results are in agreement with predicted trends in geometry, vibration frequencies and potential well-depths. A 45-point potential energy surface was calculated using IC-MRCI from which a (4,4) Padé analytical function was constructed yielding an absolute error to the fit of the surface (x2)¹/² of 3.88 cm⁻¹. 2010-04-27T05:24:04.989Z ]]>