Market transparency and collusion: on the UK agricultural tractor registration exchange

We review the decision by the European Commission in the case of the UK Agricultural Registration Exchange. We propose a theoretical model, offering a basis for some of the intuitive arguments used by the Commission on the anti-competitive role of information exchange in the case of price and non price collusion. Market transparency on non price data is shown to be a collusion facilitating device which may achieve stability in otherwise unstable cartels.

Control and chaos for vibro-impact and non-ideal oscillators

In the paper, we discuss dynamics of two kinds of mechanical systems. Initially, we consider vibro-impact systems which have many implementations in applied mechanics, ranging from drilling machinery and metal cutting processes to gear boxes. Moreover, from the point of view of dynamical systems, vibro-impact systems exhibit a rich variety of phenomena, particularly chaotic motion. In this paper, we review recent works on the dynamics of vibro-impact systems, focusing on chaotic motion and its control. The considered systems are a gear-rattling model and a smart damper to suppress chaotic motion. Furthermore, we investigate systems with non-ideal energy source, represented by a limited power supply. As an example of a non-ideal system, we analyse chaotic dynamics of the damped Duffing oscillator coupled to a rotor. Then, we show how to use a tuned liquid damper to control the attractors of this non-ideal oscillator.

Building registration: training and housing quality

The lack of attention to quality control by house builders has been a contentious issue for more than three decades. In an attempt to improve the quality of housing, various mechanisms have been adopted and discarded by industry-based organizations and government legislation. Now that registration of builders has been achieved (since 1995) the regulating authority, the Building Commission have placed the maintenance of standards from registered builders at the forefront of their priorities. The provision of suitable training and continuing professional development programs is likely to receive greater attention over the next few years. However, a key factor that is often overlooked in the debate on quality of house construction is the use of subcontract labour by both, registered builders and owner builders. The repetitive nature of some activities ensures that tacit knowledge within the subcontract system becomes an integral part of house construction. Research by the authors into defects in housing has provided some interesting analyses from the statistic collected. This paper analyses the incidence of defects over a number of years in a range of functional elements within the house envelope and presents the results. Particular attention is paid to the incidence of defects where the licensed trades are involved compared to the non-licensed trades and elements. This work suggests where housing defects are likely to occur and the authors suggest that appropriate educational resources may be directed to areas where it will be most effective and beneficial. The authors propose a more integrated and inclusive approach.

The parameter stability of a high dk rigid lens material

The use of rigid materials with high oxygen permeability (Dk) is on the increase, their major benefit being the reduction of hypoxia. However, there is a reluctance to use these materials possibly due to increased surface scratching, reduced wettability, increased deposition, reduced life expectancy and parameter instability. Considering parameter stability, various studies have demonstrated contradictory results or used high Dk materials based on the silicone acrylate polymer. This study was designed to investigate whether the parameters of a high Dk rigid fluorocarbon contact lens material changed during daily wear and extended wear schedules. Thirty five subjects, divided into group groups, Group I wore the lens on a daily wear basis, whereas those in Group II wore the lens on a monthly extended wear basis. The parameters and integrity of the lenses were monitored in both groups every 3 months. For lens integrity a statistically significant increase in surface scratching was demonstrated for the lenses worn by the subjects of both groups over the time of the study (Group I, F=7.990, P <0.0001 [ANCOVA]; Group II, F=6.241, P=0.003 [ANCOVA]). The only parameter to show a statistically significant variation over the study period was that of centre thickness for the lenses worn by the subjects in Group I (F=3.976, P=0.0063 [ANCOVA]), with a mean reduction in centre thickness of 0.022 mm at the 12 month visit.

No change was noted for either group or between groups for the other parameters measured. This study demonstrates that the parameters of rigid contact lenses manufactured from high Dk fluorocarbons are stable with only a non-clinically significant reduction in centre thickness for the contact lenses worn by the subjects in Group I.

Estimating fatality rates in occupational light vehicle users using vehicle registration and crash data

Objective: To estimate occupational light vehicle (OLV) fatality numbers using vehicle registration and crash data and compare these with previous estimates based on workers' compensation data. Method: New South Wales (NSW) Roads and Traffic Authority (RTA) vehicle registration and crash data were obtained for 2004. NSW is the only Australian jurisdiction with mandatory work-use registration, which was used as a proxy for work-relatedness. OLV fatality rates based on registration data as the denominator were calculated and comparisons made with published 2003/04 fatalities based on workers' compensation data. Results: Thirty-four NSW RTA OLV-user fatalities were identified, a rate of 4.5 deaths per 100,000 organisationally registered OLV, whereas the Australian Safety and Compensation Council (ASCC), reported 28 OLV deaths Australia-wide. Conclusions: More OLV user fatalities were identified from vehicle registration-based data than those based on workers' compensation estimates and the data are likely to provide an improved estimate of fatalities specific to OLV use. Implications: OLV-use is an important cause of traumatic fatalities that would be better identified through the use of vehicle-registration data, which provides a stronger evidence base from which to develop policy responses.

Web-based alcohol screening and brief intervention for Māori and non-Māori: the New Zealand e-SBINZ trials

BACKGROUND: Hazardous alcohol consumption is a leading modifiable cause of mortality and morbidity among young people. Screening and brief intervention (SBI) is a key strategy to reduce alcohol-related harm in the community, and web-based approaches (e-SBI) have advantages over practitioner-delivered approaches, being cheaper, more acceptable, administrable remotely and infinitely scalable. An efficacy trial in a university population showed a 10-minute intervention could reduce drinking by 11% for 6 months or more among 17-24 year-old undergraduate hazardous drinkers. The e-SBINZ study is designed to examine the effectiveness of e-SBI across a range of universities and among Māori and non-Māori students in New Zealand. METHODS/DESIGN: The e-SBINZ study comprises two parallel, double blind, multi-site, individually randomised controlled trials. This paper outlines the background and design of the trial, which is recruiting 17-24 year-old students from seven of New Zealand's eight universities. Māori and non-Māori students are being sampled separately and are invited by e-mail to complete a web questionnaire including the AUDIT-C. Those who score >4 will be randomly allocated to no further contact until follow-up (control) or to assessment and personalised feedback (intervention) via computer. Follow-up assessment will occur 5 months later in second semester. Recruitment, consent, randomisation, intervention and follow-up are all online. Primary outcomes are (i) total alcohol consumption, (ii) frequency of drinking, (iii) amount consumed per typical drinking occasion, (iv) the proportions exceeding medical guidelines for acute and chronic harm, and (v) scores on an academic problems scale. DISCUSSION: The trial will provide information on the effectiveness of e-SBI in reducing hazardous alcohol consumption across diverse university student populations with separate effect estimates for Māori and non-Māori students. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12610000279022.

Improving availability, promotion and purchase of fruit and vegetable and non sugar-sweetened drink products at community sporting clubs: a randomised trial

BACKGROUND: Amateur sporting clubs represent an attractive setting for health promotion. This study assesses the impact of a multi-component intervention on the availability, promotion and purchase of fruit and vegetable and non sugar -sweetened drink products from community sporting club canteens. We also assessed the impact the intervention on sporting club revenue from the sale of food and beverages. METHOD: A repeat cross-sectional, parallel group, cluster randomized controlled trial was undertaken with amateur community football clubs in New South Wales, Australia. The intervention was conducted over 2.5 winter sporting seasons and sought to improve the availability and promotion of fruit and vegetables and non sugar-sweetened drinks in sporting club canteens. Trial outcomes were assessed via telephone surveys of sporting club representatives and members. RESULTS: Eighty five sporting clubs and 1143 club members participated in the study. Relative to the control group, at follow-up, clubs allocated to the intervention were significantly more likely to have fruit and vegetable products available at the club canteen (OR = 5.13; 95% CI 1.70-15.38), were more likely to promote fruit and vegetable selection using reduced pricing and meal deals (OR = 34.48; 95% CI 4.18-250.00) and members of intervention clubs were more likely to report purchase of fruit and vegetable (OR = 2.58 95% CI; 1.08-6.18) and non sugar -sweetened drink (OR = 1.56; 95% CI 1.09-2.25) products. There was no significant difference between groups in the annual club revenue from food and non-alcoholic beverage sales. CONCLUSION: The findings demonstrate that the intervention can improve the nutrition environment of sporting clubs and the purchasing behaviour of members. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12609000224224 .

Efficient and accurate set-based registration of time-separated aerial images

This paper addresses the task of time-separated aerial image registration. The ability to solve this problem accurately and reliably is important for a variety of subsequent image understanding applications. The principal challenge lies in the extent and nature of transient appearance variation that a land area can undergo, such as that caused by the change under illumination conditions, seasonal variations, or the occlusion by non-persistent objects (people, cars). Our work introduces several major novelties (i) unlike previous work on aerial image registration, we approach the problem using a set-based paradigm; (ii) we show how image space local, pair-wise constraints can be used to enforce a globally good registration using a constraints graph structure; (iii) we show how a simple holistic representation derived from raw aerial images can be used as a basic building block of the constraints graph in a manner which achieves both high registration accuracy and speed; (iv) lastly, we introduce a new and, to the best of our knowledge, the only data corpus suitable for the evaluation of set-based aerial image registration algorithms. Using this data set, we demonstrate (i) that the proposed method outperforms the state-of-the-art for pair-wise registration already, achieving greater accuracy and reliability, while at the same time reducing the computational cost of the task and (ii) that the increase in the number of available images in a set consistently reduces the average registration error, with a major difference already for a single additional image.

Groupwise registration of aerial images

This paper addresses the task of time separated aerial image registration. The ability to solve this problem accurately and reliably is important for a variety of subsequent image understanding applications. The principal challenge lies in the extent and nature of transient appearance variation that a land area can undergo, such as that caused by the change in illumination conditions, seasonal variations, or the occlusion by non-persistent objects (people, cars). Our work introduces several novelties: (i) unlike all previous work on aerial image registration, we approach the problem using a set-based paradigm; (ii) we show how local, pairwise constraints can be used to enforce a globally good registration using a constraints graph structure; (iii) we show how a simple holistic representation derived from raw aerial images can be used as a basic building block of the constraints graph in a manner which achieves both high registration accuracy and speed. We demonstrate: (i) that the proposed method outperforms the state-of-the-art for pair-wise registration already, achieving greater accuracy and reliability, while at the same time reducing the computational cost of the task; and (ii) that the increase in the number of available images in a set consistently reduces the average registration error.

Levels of DNA damage in blood leukocyte samples from non-diabetic and diabetic female rats and their fetuses exposed to air or cigarette smoke

dThe objective of the present study was to evaluate DNA damage level in blood leukocytes from diabetic and non-diabetic female Wistar rats exposed to air or to cigarette smoke, and to correlate the findings with levels of DNA damage detected in blood leukocyte samples from their fetuses. A total of 20 rats were distributed into four experimental groups: non-diabetic (control; G1) and diabetic exposed to filtered air (G2): non-diabetic (G3) and diabetic (G4) exposed to cigarette smoke. Rats placed into whole-body exposure chambers were exposed for 30 min to filtered air (control) or to tobacco smoke generated from 10 cigarettes, twice a day, for 2 months. Diabetes was induced by a pancreatic beta-cytotoxic agent, streptozotocin (40 mg/kg b.w.). At day 21 of pregnancy, each rat was anesthetized and humanely killed to obtain maternal and fetal blood samples for genotoxicity analysis using the alkaline comet assay. G2, G3 and G4 dams presented higher DNA damage values in tail moment and tail length as compared to G1 group. There was a significant positive correlation between DNA damage levels in blood leukocyte samples from G2 and G3 groups (tail moment); G3 and G4 groups (tail length) and G3 group (tail intensity) and their fetuses. Thus, this study showed the association of severe diabetes and tobacco cigarette smoke exposure did not exacerbate levels of maternal and fetal DNA damages related with only diabetes or cigarette smoke exposure. Based on the results obtained and taking into account other published data, maternal diabetes requires rigid clinical control and public health and education campaigns should be increased to encourage individuals, especially pregnant women, to stop smoking. (C) 2008 Elsevier B.V. All rights reserved.

Electromyographic activity of trunk muscles during exercises with flexible and non-flexible poles

Objective: Hand-held flexible poles which are brought into oscillation to cause alternating forces on trunk, are advocated as training devices that are supposed to solicit increased levels of stabilizing trunk muscle activity. The aim of this study was to verify this claim by comparing electromyographic (EMG) activity of trunk muscles during exercises performed with a flexible pole and a rigid pole.Methods: Twelve healthy females performed three different exercises with flexible and rigid poles. EMG activity of iliocostalis lumborum (IL), multifidus (MU), rectus abdominis (RA), external oblique (EO) and internal oblique (IO), and was continuously measured. The EMG signals were analyzed in time domain by calculation of the Root Mean Square (RMS) amplitudes over 250 ms windows. The mean RMS-values over time were normalized by the maximum RMS obtained for each muscle.Results: The IO showed a 72% greater EMG activity during the exercises performed with the flexible pole than with the rigid pole (p = 0.035). In exercises performed in standing, the IO was significantly more active than when sitting (p = 0.006).Conclusion: As intended, the cyclic forces induced by the oscillating pole did increase trunk muscle activation. However, the effect was limited and significant for the IO muscle only.

On a nonlinear and chaotic non-ideal vibrating system with shape memory alloy (SMA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A general technique to embed non-uniform discontinuities into standard solid finite elements

A general technique to embed non-uniform displacement discontinuities into standard solid finite elements is presented. The technique is based on the decomposition of the kinematic fields into a component related to the deformation of the solid portion of the element and one related to the rigid-body motion due to a displacement discontinuity. This decomposition simplifies the incorporation of discontinuity interfaces and provides a suitable framework to account for non-uniform discontinuity modes. The present publication addresses two families of finite element formulations: displacement-based and stress hybrid finite element. © 2005 Elsevier Ltd. All rights reserved.

Non-linear 3D finite element analysis of full-arch implant-supported fixed dentures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)