Alternating heat transfer between objects of large geometrical difference

The heat transfer on the surface of an object in a gas fluidised bed is sequentially and alternately induced by particle-packet and gas bubble. This phenomenon is studied with computational simulation. The particle-packet and bubble are modelled by a double particle-layers and porous medium model and a hemispherical model, respectively. The heat transfer to and within the object is simulated concurrently. Different grid schemes are applied and different grid sizes are used in meshing the particle-packet and the object as there is a very large difference in their geometrical sizes. Based on theoretical analysis, an approximate method is developed to calculate the heat flux at the surface of the object. The simulation is implemented in a CFD package and the results are compared with experiments.

Increased versican content is associated with tendinosis pathology in the patellar tendon of athletes with jumper

Expansion of the extracellular matrix is a prominent but poorly characterized feature of tendinosis. The present study aimed to characterize the extent and distribution of the large aggregating proteoglycan versican in patients with patellar tendinosis. We obtained tendon from tendinopathy patients undergoing debridement of the patellar tendon and from controls undergoing intramedullary tibial nailing. Versican content was investigated by Western blotting and immunohistochemistry. Microvessel thickness and density were determined using computer-assisted image analysis. Markers for smooth muscle actin, endothelial cells (CD31) and proliferating cells (Ki67) were examined immunohistochemically. Western blot analysis and immunohistochemical staining revealed elevated versican content in the proximal patellar tendon of tendinosis patients (P=0.042). Versican content was enriched in regions of fibrocartilage metaplasia and fibroblast proliferation, as well as in the perivascular matrix of proliferating microvessels and within the media and intima of arterioles. Microvessel density was higher in tendinosis tissue compared with control tissue. Versican deposition is a prominent feature of patellar tendinosis. Because this molecule is not only a component of normal fibrocartilagenous matrices but also implicated in a variety of soft tissue pathologies, future studies should further detail both pathological and adaptive roles of versican in tendons.

Prolonged submaximal exercise induces isoform-specific Na+-K+-ATPase mRNA and protein responses in human skeletal muscle

This study investigated effects of prolonged submaximal exercise on Na⁺-K⁺-ATPase mRNA and protein expression, maximal activity, and content in human skeletal muscle. We also investigated the effects on mRNA expression of the transcription initiator gene, RNA polymerase II (RNAP II), and key genes involved in protein translation, eukaryotic initiation factor-4E (eIF-4E) and 4E-binding protein 1 (4E-BP1). Eleven subjects (6 men, 5 women) cycled at 75.5% (SD 4.8%) peak O₂ uptake and continued until fatigue. A vastus lateralis muscle biopsy was taken at rest, fatigue, and 3 and 24 h postexercise. We analyzed muscle for Na⁺-K⁺-ATPase α1, α2, α3, β1, β2, and β3, as well for RNAP II, eIF-4E, and 4E-BP1 mRNA expression by real-time RT-PCR and Na⁺-K⁺-ATPase isoform protein abundance using immunoblotting. Muscle homogenate maximal Na⁺-K⁺-ATPase activity was determined by 3-O-methylfluorescein phosphatase activity and Na⁺-K⁺-ATPase content by [³H]ouabain binding. Cycling to fatigue [54.5 (SD 20.6) min] immediately increased {alpha}3 (P = 0.044) and {beta}2 mRNA (P = 0.042) by 2.2- and 1.9-fold, respectively, whereas {alpha}1 mRNA was elevated by 2.0-fold at 24 h postexercise (P = 0.036). A significant time main effect was found for α3 protein abundance (P = 0.046). Exercise transiently depressed maximal Na⁺-K⁺-ATPase activity (P = 0.004), but Na⁺-K⁺-ATPase content was unaltered throughout recovery. Exercise immediately increased RNAP II mRNA by 2.6-fold (P = 0.011) but had no effect on eIF-4E and 4E-BP1 mRNA. Thus a single bout of prolonged submaximal exercise induced isoform-specific Na⁺-K⁺-ATPase responses, increasing α1, α3, and β2 mRNA but only α3 protein expression. Exercise also increased mRNA expression of RNAP II, a gene initiating transcription, but not of eIF-4E and 4E-BP1, key genes initiating protein translation.

The occurrence of trans-18:1 isomers in plasma lipids classes in humans

Objective: The aim of this study was to examine the distribution of trans fatty acids (TFA) in plasma lipid classes and the relationship with dietary intake of TFA.

Design: After a 2 week baseline (habitual) diet, all subjects consumed a moderate fat (MF) diet for 3 weeks with the fat being derived mainly from margarine and the rest from lean beef, and then a very low fat (VLF) diet for 3 weeks with the TFA being derived only from the lean beef. Blood samples were collected 2 days prior to the end and also on the last day of each dietary period.

Setting: Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.

Subjects: Ten free-living mildly hypercholesterolaemic subjects aged 22-66 were recruited in Geelong.

Outcome measures: TFA intake was calculated from analyses of Australian margarines, butter, lean meat and animal fat. The TFA in plasma lipid fractions were separated by AgNO3 thin-layer chromatography and quantitated by capillary gas-liquid chromatography using internal standards.

Results: The phospholipid (PL) fraction contained more than 60% of the trans-18:1 isomers in the plasma lipids in all subjects. On the baseline diet, the predominant positional isomer of trans-18:1 in PL was Delta11, whereas in the other lipid classes it was the Delta9 isomer. The concentration of the Delta9 isomer increased on the MF diet, particularly in the PL fraction, while the concentration of the Delta11 isomer decreased in all fractions. On the VLF diet, the total TFA level decreased by approximately 50%, mainly due to decreases in the TFA isomers in the PL and TG fractions. Changes in plasma total and PL TFA, PL Delta9, Delta10 and Delta11 were strongly correlated with dietary TFA intake (P<0.0001). There were also significant association between dietary TFA intake and PL Delta12 (P=0.003), triacylglycerol Delta9 (P=0.009), Delta11 (P=0.0005), total triacylglycerol (P=0.023) and free fatty acid TFA (P=0.042).

Conclusions: The results suggest that the measurement of trans-18:1 in plasma PL and TAG, and plasma total TFA could be used to estimate the intake of TFA.

Renal transplantation in patients with primary immunoglobulin A nephropathy

Background. Opinions on the clinical course and outcome of renal transplantation in patients with primary immunoglobulin A nephropathy (IgAN) have been controversial.
Methods. We conducted a retrospective single-centre study on 542 kidney transplant recipients over the period 1984–2001. Long-term outcome and factors affecting recurrence in recipients with primary IgAN were analysed.
Results. Seventy-five patients (13.8%) had biopsy-proven IgAN as the cause of renal failure, and their mean duration of follow-up after transplantation was 100 ± 5.8 months. Fourteen (18.7%) of the 75 patients had biopsy-proven recurrent IgAN, diagnosed at 67.7 ± 11 months after transplantation. The risk of recurrence was not associated with HLA DR4 or B35. Graft failure occurred in five (35.7%) of the 14 patients: three due to IgAN and two due to chronic rejection. Three (4.9%) of the 61 patients without recurrent IgAN had graft failure, all due to chronic rejection. Graft survival was similar between living-related and cadaveric/living-unrelated patients (12-year graft survival, 88 and 72%, respectively, P = 0.616). Renal allograft survival within the first 12 years was better in patients with primary IgAN compared with those with other primary diseases (80 vs 51%, P = 0.001). Thereafter, IgAN patients showed an inferior graft survival (74 vs 97% in non-IgAN patients, P = 0.001).
Conclusions. Our data suggested that around one-fifth of patients with primary IgAN developed recurrence by 5 years after transplantation. Recurrent IgA nephropathy in allografts runs an indolent course with favourable outcome in the first 12 years. However, the contribution of recurrent disease to graft loss becomes more significant on long-term follow up.

Contact pressure evolution and its relation to wear in sheet metal forming

For a given sheet metal forming process, an accurate determination of the contact pressure distribution is an essential step towards the estimation of tool life. This investigation utilizes finite element (FE) analysis to model and explain the evolution and distribution of contact pressure over the die radius, throughout the duration of a channel forming process. It was found that a typical two-peak steady-state contact pressure response exists for the majority of the process. However, this was preceded by an initial transient response, characterized by extremely large and localized contact pressures, which were more than double the magnitude of the steady-state peak pressure. The validity of the predicted contact pressure behavior was assessed via detailed numerical analysis and by examining the wear response of an experimental stamping operation. The experimental results revealed that the high contact pressure zones of the transient response corresponded to a severe galling wear mechanism. Therefore, the transient response may be of primary significance to the tool wear response; thus questioning the applicability of traditional bending-under-tension wear tests for sheet metal stamping processes. Finally, a parametric study was conducted, examining the influence of the major process parameters on the steady-state and peak transient contact pressures, using the developed FE model. It was found that the bend ratio and the blank material ultimate tensile strength had the most influence on the peak contact pressures. The main process-related parameters, friction coefficient and blank holder force, were found to have only a minor influence.

Indigenous performing arts and the problem of judging 'excellence': A discussion paper

In this paper we look at the persistent debate over notions of access and excellence and intrinsic and instrumentalist rationales for arts practice within cultural policy discussion. Recent research into the Indigenous performing arts in Australia underlines the particular difficulties faced by the sector in balancing the demands of community participation, social inclusion and high-quality aesthetic outcomes. The balancing act has proven unsustainable for some Indigenous performing arts companies and their viability is now in doubt. This suggests that a re-consideration of the question of the purpose and value of the Indigenous performing arts is timely.

On the electrochemical response and interfacial properties of steel–Ca(OH)2 and the steel–concrete system measured using galvanostatic pulses

The interfacial properties of the steel–concrete system are examined via a new approach for evaluation of galvanostatic pulse data. This methodology allows for rapid determination of the corrosion activity of steel, and readily yields values for parameters related to corrosion such as the polarisation resistance and interfacial capacitance. The method of analysis is based on the iterative fitting of a non-exponential model based on a modified Kohlrausch–Williams–Watt (KWW) formalism. The transient behaviour of steel in concrete is non-exponential in its form and, when analysed this way, an exponent β can be determined characterising the exponential non-ideality of the transient. This non-ideality parameter is found to differ significantly for actively corroding and passive specimens, thereby serving as a useful index to the level of corrosion being experienced. Furthermore, the investigation of the interfacial characteristics of the system, previously unobtainable in a reproducible manner via other electrochemical methods, reveal information regarding the kinetic factors governing corrosion of steel in concrete.

Ionic conduction in doped succinonitrile

Doping of lithium salts into the plastic crystal phase of succinonitrile does significantly increase ionic conductivity. This paper investigates the effect of anion (TFSA, Tf and BF₄) on the conductivity and diffusion of the mobile species using impedance spectroscopy and NMR. Room temperature conductivities up to 2.1×10⁻⁴ S cm⁻¹ were obtained with 1 mol% lithium bis(trifluoromethanesulfonyl)amide in succinonitrile. Pulse field gradient NMR has shown that in all three systems investigated, both cation and anion are mobile in this lattice.

Relationship of weaning weight to the mature liveweight of cashmere does on Australian farms

Median weaning weight and its relationship with the median mature liveweight of does was quantified for four commercial Australian cashmere farms in various parts of Australia. Individual liveweights, of does of all ages at the time of weaning in December, ranged from 9 to 61 kg. Individual farm means of adult does (>1 year old) ranged from 24.6 to 38.8 kg. The model for the logarithm of liveweight was: log₁₀(liveweight) = a + br ^{(Age + 0.6);} where a, b and r are parameters that are different for each farm. The result that the r parameter differs with farm was statistically significant (P = 9.4 10^-6). The percentage variance accounted for was 84.4% and the residual standard deviation was 0.042. Farms differed greatly in the median mature liveweight with some farms reaching ~44 kg and others only 31 kg. Median weaning weight was 14.1 kg (range 11.4-16.8 kg). Median weaning weight as a percentage of median mature doe liveweight on a particular farm varied from 32 to 42%. These weaning weights appear low in absolute and relative terms and thus are likely to incur production penalties.

The population burden of fractures originates in women with osteopenia, not osteoporosis

Introduction : Osteoporosis is associated with increased risk for fracture. However, most postmenopausal women have bone mineral density (BMD) within the normal or osteopenic range. The aim of this study was to determine the proportion of the population burden of fragility fractures arising from women at modest risk for fracture.

Methods : We measured baseline BMD in a population-based random sample of 616 postmenopausal women aged 60–94 years and followed these individuals for a median of 5.6 years (IQR 3.9–6.5) to determine the incidence of fractures according to age, BMD and the presence of a prior fracture.

Results : Based on WHO criteria, 37.6% of the women had normal total hip BMD, 48.0% had osteopenia and 14.5% had osteoporosis. The incidence of fracture during follow-up was highest in women with osteoporosis, but only 26.9% of all fractures arose from this group; 73.1% occurred in women without osteoporosis (56.5% in women with osteopenia, 16.6% in women with normal BMD). Decreasing BMD, increasing age and prior fracture contributed independently to increased fracture risk; in a multivariate model, the relative risk for fracture increased 65% for each SD decrease in BMD (RR=1.65, 95%CI 1.32–2.05), increased 3% for every year of age (RR=1.03, 95%CI 1.01–1.06) and doubled with prevalent fracture (RR=2.01, 95% CI 1.40–2.88). A prevalent fracture increased the risk for fractures such that women with osteopenia and prevalent fracture had the same, if not greater, risk as women with osteoporosis alone.