Application of autologous periosteal cells for the regeneration of class III furcation defects in Beagle dogs

The aim of this study was to evaluate the healing of class III furcation defects following transplantation of autogenous periosteal cells combined with b-tricalcium phosphate (b-TCP). Periosteal cells obtained from Beagle dogs’ periosteum explant cultures, were inoculated onto the surface of b-TCP. Class III furcation defects were created in the mandibular premolars. Three experimental groups were used to test the defects’ healing: group A, b-TCP seeded with periosteal cells were transplanted into the defects; group B, b-TCP alone was used for defect filling; and group C, the defect was without filling materials. Twelve weeks post surgery, the tissue samples were collected for histology, immunohistology and X-ray examination. It was found that both the length of newly formed periodontal ligament and the area of newly formed alveolar bone in group A, were significantly increased compared with both group B and C. Furthermore, both the proportion of newly formed periodontal ligament and newly formed alveolar bone in group A were much higher than those of group B and C. The quantity of cementum and its percentage in the defects (group A) were also significantly higher than those of group C. These results indicate that autogenous periosteal cells combined with b-TCP application can improve periodontal tissue regeneration in class III furcation defects.

Fold back current control and admittance protection scheme for a distribution network containing distributed generators

Islanded operation, protection, reclosing and arc extinguishing are some of the challenging issues related to the connection of converter interfaced distributed generators (DGs) into a distribution network. The isolation of upstream faults in grid connected mode and fault detection in islanded mode using overcurrent devices are difficult. In the event of an arc fault, all DGs must be disconnected in order to extinguish the arc. Otherwise, they will continue to feed the fault, thus sustaining the arc. However, the system reliability can be increased by maximising the DG connectivity to the system: therefore, the system protection scheme must ensure that only the faulted segment is removed from the feeder. This is true even in the case of a radial feeder as the DG can be connected at various points along the feeder. In this paper, a new relay scheme is proposed which, along with a novel current control strategy for converter interfaced DGs, can isolate permanent and temporary arc faults. The proposed protection and control scheme can even coordinate with reclosers. The results are validated through PSCAD/EMTDC simulation and MATLAB calculations.

The application of neural networks to induction machine control

Neural networks (NNs) are discussed in connection with their possible use in induction machine drives. The mathematical model of the NN as well as a commonly used learning algorithm is presented. Possible applications of NNs to induction machine control are discussed. A simulation of an NN successfully identifying the nonlinear multivariable model of an induction-machine stator transfer function is presented. Previously published applications are discussed, and some possible future applications are proposed.

Repair and regeneration of osteochondral defects in the articular joints

People suffering from pain due to osteoarthritic or rheumatoidal changes in the joints are still waiting for a better treatment. Although some studies have achieved success in repairing small cartilage defects, there is no widely accepted method for complete repair of osteochondral defects. Also joint replacements have not yet succeeded in replacing of natural cartilage without complications. Therefore, there is room for a new medical approach, which outperforms currently used methods. The aim of this study is to show potential of using a tissue engineering approach for regeneration of osteochondral defects. The critical review of currently used methods for treatment of osteochondral defects is also provided. In this study, two kinds of hybrid scaffolds developed in Hutmacher's group have been analysed. The first biphasic scaffold consists of fibrin and PCL. The fibrin serves as a cartilage phase while the porous PCL scaffold acts as the subchondral phase. The second system comprises of PCL and PCL-TCP. The scaffolds were fabricated via fused deposition modeling which is a rapid prototyping system. Bone marrow-derived mesenchymal cells were isolated from New Zealand White rabbits, cultured in vitro and seeded into the scaffolds. Bone regenerations of the subchondral phases were quantified via micro CT analysis and the results demonstrated the potential of the porous PCL and PCL-TCP scaffolds in promoting bone healing. Fibrin was found to be lacking in this aspect as it degrades rapidly. On the other hand, the porous PCL scaffold degrades slowly hence it provides an effective mechanical support. This study shows that in the field of cartilage repair or replacement, tissue engineering may have big impact in the future. In vivo bone and cartilage engineering via combining a novel composite, biphasic scaffold technology with a MSC has been shown a high potential in the knee defect regeneration in the animal models. However, the clinical application of tissue engineering requires the future research work due to several problems, such as scaffold design, cellular delivery and implantation strategies.

Assessment of the suitability of public mobile data networks for aircraft telemetry and control purposes

This paper provides a review of the state of the art relevant work on the use of public mobile data networks for aircraft telemetry and control proposes. Moreover, it describes the characterisation for airborne uses of the public mobile data communication systems known broadly as 3G. The motivation for this study was the explore how this mature public communication systems could be used for aviation purposes. An experimental system was fitted to a light aircraft to record communication latency, line speed, RF level, packet loss and cell tower identifier. Communications was established using internet protocols and connection was made to a local server. The aircraft was flown in both remote and populous areas at altitudes up to 8500 ft in a region located in South East Queensland, Australia. Results show that the average airborne RF levels are better than those on the ground by 21% and in the order of - 77dbm. Latencies were in the order of 500ms (1/2 the latency of Iridium), an average download speed of 0.48Mb/s, average uplink speed of 0.85Mb/s, a packet of information loss of 6.5%. The maximum communication range was also observed to be 70km from a single cell station. The paper also describes possible limitations and utility of using such communications architecture for both manned and unmanned aircraft systems.

Novel PCL-based honeycomb scaffolds as drug delivery systems for rhBMP-2

This study investigated a novel drug delivery system (DDS), consisting of polycaprolactone (PCL) or polycaprolactone 20% tricalcium phosphate (PCL-TCP) biodegradable scaffolds, fibrin Tisseel sealant and recombinant bone morphogenetic protein-2 (rhBMP-2) for bone regeneration. PCL and PCL-TCP-fibrin composites displayed a loading efficiency of 70% and 43%, respectively. Fluorescence and scanning electron microscopy revealed sparse clumps of rhBMP-2 particles, non-uniformly distributed on the rods’ surface of PCL-fibrin composites. In contrast, individual rhBMP-2 particles were evident and uniformly distributed on the rods’ surface of the PCL-TCP-fibrin composites. PCL-fibrin composites loaded with 10 and 20 μg/ml rhBMP-2 demonstrated a triphasic release profile as quantified by an enzyme-linked immunosorbent assay (ELISA). This consisted of burst releases at 2 h, and days 7 and 16. A biphasic release profile was observed for PCL-TCP-fibrin composites loaded with 10 μg/ml rhBMP-2, consisting of burst releases at 2 h and day 14. PCL-TCP-fibrin composites loaded with 20 μg/ml rhBMP-2 showed a tri-phasic release profile, consisting of burst releases at 2 h, and days 10 and 21. We conclude that the addition of TCP caused a delay in rhBMP-2 release. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and alkaline phosphatase assay verified the stability and bioactivity of eluted rhBMP-2 at all time points

The effect of rhBMP-2 on canine osteoblasts seeded onto 3D bioactive polycaprolactone scaffolds

Our strategy entails investigating the influence of varied concentrations (0, 10, 100 and 1000 ng/ml) of human recombinant bone morphogenetic protein-2 (rhBMP-2) on the osteogenic expression of canine osteoblasts, seeded onto poly-caprolactone 20% tricalcium phosphate (PCL-TCP) scaffolds in vitro. Biochemical assay revealed that groups with rhBMP-2 displayed an initial burst in cell growth that was not dose-dependent. However, after 13 days, cell growth declined to a value similar to control. Significantly less cell growth was observed for construct with 1000 ng/ml of rhBMP-2 from 20 days onwards. Confocal microscopy confirmed viability of osteoblasts and at day 20, groups seeded with rhBMP-2 displayed heightened cell death as compared to control. Phase contrast and scanning electron microscopy revealed that osteoblasts heavily colonized surfaces, rods and pores of the PCL-TCP scaffolds. This was consistent for all groups. Finally, Von Kossa and osteocalcin assays demonstrated that cells from all groups maintained their osteogenic phenotype throughout the experiment. Calcification was observed as early as four days after stimulation for groups seeded with rhBMP-2. In conclusion, rhBMP-2 seems to enhance the differentiated function of canine osteoblasts in a non-dose dependent manner. This resulted in accelerated mineralization, followed by death of osteoblasts as they underwent terminal differentiation. Notably, PCL-TCP scaffolds seeded only with canine osteoblasts could sustain excellent osteogenic expression in vitro. Hence, the synergy of PCL with bioactive TCP and rhBMP-2 in a novel composite scaffold, could offer an exciting approach for bone regeneration.

Comparing exercise prescribed with exercise completed : effects of gender and mode of exercise

The purpose of this study was to compare the amount of exercise prescribed with the amount completed between two different modes of training intervention and between the sexes. Thirty-two men (mean age = 39.1 years, body mass index = 32.9 kg · m-2) and women (mean age = 39.6 years, body mass index = 32.1 kg · m-2) were prescribed traditional resistance training or light-resistance circuit training for 16 weeks. Lean mass and fat mass were determined by dual-energy X-ray absorptiometry at weeks 1 and 16. A completion index was calculated to provide a measure of the extent to which participants completed exercise training relative to the amount of exercise prescribed. The absolute amount of exercise completed by the circuit training group was significantly greater than the amount prescribed (P < 0.0001). The resistance training group consistently under-completed relative to the amount prescribed, but the difference was not significant. The completion index for the circuit training group (26 ± 21.7%) was significantly different from that of the resistance training group (-7.4 ± 3.0%). The completion index was not significantly different between men and women in either group. These data suggest that overweight and obese individuals participating in light-resistance circuit training complete more exercise than is prescribed. Men and women do not differ in the extent to which they over- or under-complete prescribed exercise.

Perceptions of daylight quality delivered by light transport systems

Light Transport Systems (LTS) (e.g lightpipes, fibre optics) can illuminate core areas within buildings with great potential for energy savings. However, they do not provide a clear connection to the outside like windows do, and their effects on people’s physiological and psychological health are not well understood. Furthermore, how people perceive LTS affects users’ acceptance of the device and its performance. The purpose of this research is to understand how occupants perceive and experience spaces illuminated by LTS. Two case studies of commercial buildings with LTS, located in Brisbane, Australia are assessed by qualitative (focus group interviews) and quantitative (measurement of daylight illuminances and luminance) methods. The data from interviews with occupants provide useful insight into the aspects of LTS design that are most relevant to positive perception of the luminous environment. Luminance measurements of the occupied spaces support the perception of the LTS reported by occupants: designs that create high contrast luminous environments are more likely to be perceived negatively.

Workflows, processes and technical solutions for seeding the research data commons

Queensland University of Technology (QUT) completed an Australian National Data Service (ANDS) funded “Seeding the Commons Project” to contribute metadata to Research Data Australia. The project employed two Research Data Librarians from October 2009 through to July 2010. Technical support for the project was provided by QUT’s High Performance Computing and Research Support Specialists. ---------- The project identified and described QUT’s category 1 (ARC / NHMRC) research datasets. Metadata for the research datasets was stored in QUT’s Research Data Repository (Architecta Mediaflux). Metadata which was suitable for inclusion in Research Data Australia was made available to the Australian Research Data Commons (ARDC) in RIF-CS format. ---------- Several workflows and processes were developed during the project. 195 data interviews took place in connection with 424 separate research activities which resulted in the identification of 492 datasets. ---------- The project had a high level of technical support from QUT High Performance Computing and Research Support Specialists who developed the Research Data Librarian interface to the data repository that enabled manual entry of interview data and dataset metadata, creation of relationships between repository objects. The Research Data Librarians mapped the QUT metadata repository fields to RIF-CS and an application was created by the HPC and Research Support Specialists to generate RIF-CS files for harvest by the Australian Research Data Commons (ARDC). ---------- This poster will focus on the workflows and processes established for the project including: ---------- • Interview processes and instruments • Data Ingest from existing systems (including mapping to RIF-CS) • Data entry and the Data Librarian interface to Mediaflux • Verification processes • Mapping and creation of RIF-CS for the ARDC

Weighted fairness with MCR guarantee and a general-purpose explicit rate allocation algorithm for ATM ABR service

In this paper, weighted fair rate allocation for ATM available bit rate (ABR) service is discussed with the concern of the minimum cell rate (MCR). Weighted fairness with MCR guarantee has been discussed recently in the literature. In those studies, each ABR virtual connection (VC) is first allocated its MCR, then the remaining available bandwidth is further shared among ABR VCs according to their weights. For the weighted fairness defined in this paper, the bandwidth is first allocated according to each VC's weight; if a VC's weighted share is less than its MCR, it should be allocated its MCR instead of the weighted share. This weighted fairness with MCR guarantee is referred to as extended weighted (EXW) fairness. Certain theoretical issues related to EXW, such as its global solution and bottleneck structure, are first discussed in the paper. A distributed explicit rate allocation algorithm is then proposed to achieve EXW fairness in ATM networks. The algorithm is a general-purpose explicit rate algorithm in the sense that it can realise almost all the fairness principles proposed for ABR so far whilst only minor modifications may be needed.

Navigating technological contexts and experience design in music education

For some time we have jokingly referred to our network jamming research with jam2jam as ‘Switched on Orff’ (Brown, Sorensen and Dillon 2002; Dillon 2003; Dillon 2006; Dillon 2006; Brown and Dillon 2007). The connection with electronic music and Wendy Carlos’ classic work ‘Switched on Bach’ was obvious; we were using electronic music in schools and with children. The deeper connection with Orff however was about recognising that electronic music and instruments could have cultural values and knowledge embedded in their design and practice in same way as what has come to be known as the Orff method (Orff and Keetman 1958-66). However whilst the Orff method focuses upon Western art music perceptual framework electronic instruments have the potential to have more fluid musical environments and even to move to interdisciplinary study by including visual media. Whilst the Orff method focused on making sense of Western art music through experience electronic environments potentially can make sense of the world of multi media that pervades our lives.

Reinforcing bad behaviour : the misuse of security indicators on popular websites

Before making a security or privacy decision, Internet users should evaluate several security indicators in their browser, such as the use of HTTPS (indicated via the lock icon), the domain name of the site, and information from extended validation certificates. However, studies have shown that human subjects infrequently employ these indicators, relying on other indicators that can be spoofed and convey no cryptographic assurances. We identify four simple security indicators that accurately represent security properties of the connection and then examine 125 popular websites to determine if the sites' designs result in correctly displayed security indicators during login. In the vast majority of cases, at least some security indicators are absent or suboptimal. This suggests users are becoming habituated to ignoring recommended security indicators.