Resection-intersection bundle adjustment revisited

Bundle adjustment is one of the essential components of the computer vision toolbox. This paper revisits the resection-intersection approach, which has previously been shown to have inferior convergence properties. Modifications are proposed that greatly improve the performance of this method, resulting in a fast and accurate approach. Firstly, a linear triangulation step is added to the intersection stage, yielding higher accuracy and improved convergence rate. Secondly, the effect of parameter updates is tracked in order to reduce wasteful computation; only variables coupled to significantly changing variables are updated. This leads to significant improvements in computation time, at the cost of a small, controllable increase in error. Loop closures are handled effectively without the need for additional network modelling. The proposed approach is shown experimentally to yield comparable accuracy to a full sparse bundle adjustment (20% error increase) while computation time scales much better with the number of variables. Experiments on a progressive reconstruction system show the proposed method to be more efficient by a factor of 65 to 177, and 4.5 times more accurate (increasing over time) than a localised sparse bundle adjustment approach.

Identity-based signcryption

The notion of identity-based IB cryptography was proposed by Shamir [177] as a specialization of public key PK cryptography which dispensed with the need for cumbersome directories, certificates, and revocation lists.

EdU, a new thymidine analogue for labelling proliferating cells in the nervous system

The standard method of labelling proliferating cells uses the thymidine analogue, bromodeoxyuridine (BrdU), which incorporates into the DNA during S-phase of the cell cycle. A disadvantage of this method is that the immunochemical processing requires pre-treatment of the cells and tissue with heat or acid to reveal the antigen. This pre-treatment reduces reliability of the method and degrades the specimen, reducing the ability for multiple immuno-fluorescence labelling at high resolution. We report here the utility of a novel thymidine analogue, ethynyl deoxyuridine (EdU), detected with a fluorescent azide via the “click” chemistry reaction (the Huisgen 1,3-dipolar cycloaddition reaction of an organic azide to a terminal acetylene). The detection of EdU requires no heat or acid treatment and the incorporated EdU is covalently conjugated to fluorescent probe. The reaction is quick and compatible with fluorescence immunochemistry and other fluorescent probes. We show here that EdU is non-toxic in vitro and in vivo and can be used in place of BrdU to label cells during neurogenesis and the progeny identified at least 30 days later. The fluorescent labelling of EdU, markedly improves the detection of proliferating cells and allows concurrent high resolution fluorescence immunochemistry.

Curriculum to the classroom : investigating the spatial practices of curriculum implementation in Queensland schools and its implications for teacher education

Change is something that both pre-service and practising teachers face regularly throughout their professional lives. Curriculum change and consequential implementation is a case in point. This paper investigates the perspectives of a number of school-based stakeholders in regard to the implementation of the C2C materials in Queensland schools and how this has potential consequences for teacher education programs. It shows that often contradictory spaces emerge in regard to curriculum enactment and argues that a ‘one size fits all’ approach is not the most effective way to implement new curriculum. A transformative third space is offered whereby teachers are accorded with a voice in the way in which implementation occurs; ultimately allowing pre-service teachers to learn important skills required to be effective teachers.

Unusual cross-ring S(N)2 reactions of M-H (-) ions of methoxyacetanilides

Deprotonated o, m-, and p-methoxyacetanilide show pronounced peaks in their collision-induced tandem mass spectra (MS/MS) produced by losses of the elements of C2H6. It is proposed that this reaction is a 'cross-ring' internal S(N)2 reaction involving an incipient methyl anion. For example, p-CH3O-C6H4-N--CO-CH3--> [(p.CH3O-C6H4-N=C=O)CH3-]--> O---C6H4-N=C=O+C2H6.

An Introduction to Constrained Control

An ubiquitous problem in control system design is that the system must operate subject to various constraints. Although the topic of constrained control has a long history in practice, there have been recent significant advances in the supporting theory. In this chapter, we give an introduction to constrained control. In particular, we describe contemporary work which shows that the constrained optimal control problem for discrete-time systems has an interesting geometric structure and a simple local solution. We also discuss issues associated with the output feedback solution to this class of problems, and the implication of these results in the closely related problem of anti-windup. As an application, we address the problem of rudder roll stabilization for ships.

Unusual cross-ring SN2 reactions of [MH]− ions of methoxyacetanilides

Deprotonated o, m-, and p-methoxyacetanilide show pronounced peaks in their collision-induced tandem mass spectra (MS/MS) produced by losses of the elements of C2H6. It is proposed that this reaction is a 'cross-ring' internal S(N)2 reaction involving an incipient methyl anion. For example, p-CH3O-C6H4-N--CO-CH3--> [(p.CH3O-C6H4-N=C=O)CH3-]--> O---C6H4-N=C=O+C2H6.

Time kinetics of bone defect healing in response to BMP-2 and GDF-5 characterised by in vivo biomechanics

This study reports that treatment of osseous defects with different growth factors initiates distinct rates of repair. We developed a new method for monitoring the progression of repair, based upon measuring the in vivo mechanical properties of healing bone. Two different members of the bone morphogenetic protein (BMP) family were chosen to initiate defect healing: BMP-2 to induce osteogenesis, and growth-and-differentiation factor (GDF)-5 to induce chondrogenesis. To evaluate bone healing, BMPs were implanted into stabilised 5 mm bone defects in rat femurs and compared to controls. During the first two weeks, in vivo biomechanical measurements showed similar values regardless of the treatment used. However, 2 weeks after surgery, the rhBMP-2 group had a substantial increase in stiffness, which was supported by the imaging modalities. Although the rhGDF-5 group showed comparable mechanical properties at 6 weeks as the rhBMP-2 group, the temporal development of regenerating tissues appeared different with rhGDF-5, resulting in a smaller callus and delayed tissue mineralisation. Moreover, histology showed the presence of cartilage in the rhGDF-5 group whereas the rhBMP-2 group had no cartilaginous tissue. Therefore, this study shows that rhBMP-2 and rhGDF-5 treated defects, under the same conditions, use distinct rates of bone healing as shown by the tissue mechanical properties. Furthermore, results showed that in vivo biomechanical method is capable of detecting differences in healing rate by means of change in callus stiffness due to tissue mineralisation.

When should private property rights give way to the public interest?

Since Queensland Wire Industries Pty Ltd v Broken Hill Pty Co Ltd (1989) 167 CLR 177 it has been recognised that corporations with substantial market power are subject to special responsibilities and restraints that corporations without market power are not. In NT Power Generation Pty Ltd v Power and Water Authority (2004) 219 CLR 90 McHugh A-CJ, Gummow, Callinan and Heydon JJ in their joint reasons stated (at [76]), that s 46 of the Competition and Consumer Act 2010 (Cth) (CCA) can operate not only to prevent firms with substantial market power from doing prohibited things, but also compel them positively to do things they do not want to do. Their Honours also stated (at [126]) that the proposition that a private property owner who declines to permit competitors to use the property is immune from s 46 is “intrinsically unsound”. However, the circumstances in which a firm with substantial power must accommodate competitors, and private property rights give way to the public interest are uncertain. The purpose of this Note is to consider recent developments in two areas of the CCA where the law requires private property rights to give way to the public interest. The first part of the Note considers two recent cases which clarify the circumstances in which s 46 of the CCA can be used to compel a firm with substantial market power to accommodate a competitor and allow the competitor to make use of private property rights in the public interest. Secondly, on 12 February 2014 the Minister for Small Business, the Hon Bruce Billson,released the Productivity Commission’s Final Report, on the National Access Regime in Pt IIIA of the CCA (National Access Regime, Inquiry Report No 66, Canberra). Pt IIIA provides for the processes by which third parties may obtain access to infrastructure owned by others in the public interest. The Report recommends that Pt IIIA be retained but makes a number of suggestions for its reform, some of which will be briefly considered.

Commissioning of a new commercial plastic scintillator system for radiotherapy

Introduction Since 1992 there have been several articles published on research on plastic scintillators for use in radiotherapy. Plastic scintillators are said to be tissue equivalent, temperature independent and dose rate independent [1]. Although their properties were found to be promising for measurements in megavoltage X-ray beams there were some technical difficulties with regards to its commercialisation. Standard Imaging has produced the first commercial system which is now available for use in a clinical setting. The Exradin W1 scintillator device uses a dual fibre system where one fibre is connected to the Plastic Scintillator and the other fibre only measures Cerenkov radiation [2]. This paper presents results obtained during commissioning of this dosimeter system. Methods All tests were performed on a Novalis Tx linear accelerator equipped with a 6 MV SRS photon beam and conventional 6 and 18 MV X-ray beams. The following measurements were performed in a Virtual Water phantom at a depth of dose maximum. Linearity: The dose delivered was varied between 0.2 and 3.0 Gy for the same field conditions. Dose rate dependence: For this test the repetition rate of the linac was varied between 100 and 1,000 MU/min. A nominal dose of 1.0 Gy was delivered for each rate. Reproducibility: A total of five irradiations for the same setup. Results The W1 detector gave a highly linear relationship between dose and the number of Monitor Units delivered for a 10 9 10 cm2 field size at a SSD of 100 cm. The linearity was within 1 % for the high dose end and about 2 % for the very low dose end. For the dose rate dependence, the dose measured as a function of repetition the rate (100–1,000 MU/min) gave a maximum deviation of 0.9 %. The reproducibility was found to be better than 0.5 %. Discussion and conclusions The results for this system look promising so far being a new dosimetry system available for clinical use. However, further investigation is needed to produce a full characterisation prior to use in megavoltage X-ray beams.

High and low mammographic density human breast tissues maintain histological differential in murine tissue engineering chambers

Mammographic density (MD) is the area of breast tissue that appears radiologically white on mammography. Although high MD is a strong risk factor for breast cancer, independent of BRCA1/2 mutation status, the molecular basis of high MD and its associated breast cancer risk is poorly understood. MD studies will benefit from an animal model, where hormonal, gene and drug perturbations on MD can be measured in a preclinical context. High and low MD tissues were selectively sampled by stereotactic biopsy from operative specimens of high-risk women undergoing prophylactic mastectomy. The high and low MD tissues were transferred into separate vascularised biochambers in the groins of SCID mice. Chamber material was harvested after 6 weeks for histological analyses and immunohistochemistry for cytokeratins, vimentin and a human-specific mitochondrial antigen. Within-individual analysis was performed in replicate mice, eliminating confounding by age, body mass index and process-related factors, and comparisons were made to the parental human tissue. Maintenance of differential MD post-propagation was assessed radiographically. Immunohistochemical staining confirmed the preservation of human glandular and stromal components in the murine biochambers, with maintenance of radiographic MD differential. Propagated high MD regions had higher stromal (p = 0.0002) and lower adipose (p = 0.0006) composition, reflecting the findings in the original human breast tissue, although glands appeared small and non-complex in both high and low MD groups. No significant differences were observed in glandular area (p = 0.4) or count (p = 0.4) between high and low MD biochamber tissues. Human mammary glandular and stromal tissues were viably maintained in murine biochambers, with preservation of differential radiographic density and histological features. Our study provides a murine model for future studies into the biomolecular basis of MD as a risk factor for breast cancer.

Probing the surface oxidation of chemically synthesised gold nanospheres and nanorods

In this study, the electrochemical behaviour of commercially available gold spheres and rods stabilised by carboxylic acid and cetyl trimethyl ammonium bromide (CTAB) moieties, respectively, are investigated. The cyclic voltammetric behaviour in acidic electrolyte is distinctly different with the nanorods exhibiting unusual oxidative behaviour due to an electrodissolution process. The nanospheres exhibited responses typical of a highly defective surface which significantly impacted on electrocatalytic activity. A repetitive potential cycling cleaning procedure was also investigated which did not improve the activity of the nanorods and resulted in deactivating the gold spheres due to decreasing the level of surface defects.

Agreement between student-reported and proxy-reported physical activity questionnaires

Parents and 531 students (46% males, 78% white) completed equivalent questionnaires. Agreement between student and parent responses to questions about hypothesized physical activity (PA) correlates was assessed. Relationships between hypothesized correlates and an objective measure of student's moderate-to-vigorous physical activity (MVPA) in a subset of 177 students were also investigated. Agreement between student and parent ranged from r = .34 to .64 for PA correlates. Spearman correlations between MVPA and PA correlates ranged from –.04 to .21 for student report and –.14 to .32 for parent report, and there were no statistical differences for 8 out of 9 correlations between parent and student. Parents can provide useful data on PA correlates for students in Grades 7–12.