The preventive effects of systemic casein phosphopeptides on the resorption of roots in rats

Introduction: Root resorption is a well documented side effect of orthodontic treatment. The aim of this study is to assess the potential for casein phosphopeptides (CPPs) to create an environment in which teeth are less susceptible to root resorption following orthodontic tooth movement. Method: Thirty one eleven week old, Wistar rats, were used in this experiment. Experimental and control animals were given the same diet of nutrigel (Troy Laboratories Pty. Ltd, NSW, Australia) mixed with rat chow with the same frequency and had free access to water throughout the whole experimental period. The 14 experimental rats received a diet supplemented with 40mg CPP per 100g of rat while the 17 control rats did not receive any supplements in their diet. The rats underwent a 2-week period of acclimatization with their respective diets followed by a two week experimental period after which the animals were euthanized and the samples were harvested. The tooth movement appliance was a 150cN sentalloy® (GAC Australia) closed coil spring (wire diameter 0.22mm, eyelet diameter 0.56 mm) applied from the maxillary incisor randomly to the right and left first maxillary molar. A volumetric analysis of the extent of root resorption on the mesial root of the first maxillary molar was examined using a micro CT scan. Results: The rats which received dietary CPP did not have a significant reduction in overall root resorption (p=0.28) although the results did reveal that dietary CPP appeared to lower the average root resorption by about a 15%. Dietary CPP was also found to have no statistically significant effect on decreasing tooth movement (p=0.42) although the average tooth movement was reduced by about 15%. Conclusions: CPP seems to have a variable effect on the volumetric quantification of root resorption. While on average, there was less root resorption observed in rats fed dietary CPP, individual variability makes this effect statistically insignificant. Similarly, CPP did not have a statistically significant effect on reducing tooth movement. Although it is possible that CPP may have a beneficial effect on reducing cementum solubility, this may be counteracted by its anabolic effect on bone mass which explains the variability observed in this study

Analysis of movement variability in cycling : An exploratory study

The purpose of this study was to determine the test-retest repeatability of Blue Trident inertial measurement units (IMUs) and VICON Nexus kinematic modelling in analysing the Lyapunov Exponent (LyE) during a maximal effort 4000 m cycling bout in different body segments/joints. An additional aim was to determine if changes in the LyE existed across a trial. Twelve novice cyclists completed four sessions of cycling; one was a familiarisation session to determine a bike fit and become better accustomed to the time trial position and pacing of a 4000 m effort. IMUs were attached to the head, thorax, pelvis and left and right shanks to analyse segment accelerations, respectively, and reflective markers were attached to the participant to analyse neck, thorax, pelvis, hip, knee and ankle segment/joint angular kinematics, respectively. Both the IMU and VICON Nexus test-retest repeatability ranged from poor to excellent at the different sites. In each session, the head and thorax IMU acceleration LyE increased across the bout, whilst pelvic and shank acceleration remained consistent. Differences across sessions were evident in VICON Nexus segment/joint angular kinematics, but no consistent trend existed. The improved reliability and the ability to identify a consistent trend in performance, combined with their improved portability and reduced cost, advocate for the use of IMUs in analysing movement variability in cycling. However, additional research is required to determine the applicability of analysing movement variability during cycling

Estimating and validating koala Phascolarctos cinereus density estimates from acoustic arrays using spatial count modelling

Context: It is notoriously difficult to estimate the size of animal populations, especially for cryptic or threatened species that occur in low numbers. Recent advances with acoustic sensors make the detection of animal populations cost effective when coupled with software that can recognise species-specific calls. Aims: We assess the potential for acoustic sensors to estimate koala, Phascolarctos cinereus, density, when individuals are not identified, using spatial count models. Sites were selected where previous independent estimates of density were available. Methods: We established acoustic arrays at each of five sites representing different environments and densities of koalas in New South Wales. To assess reliability, we compared male koala density estimates derived from spatial count modelling to independently derived estimates for each site. Key results: A total 11 312 koala bellows were verified across our five arrays. Koalas were detected at most of our sample locations (96-100% of sensors; n = 130), compared with low detection rates from rapid scat searches at trees near each sensor (scats at Conclusions: Spatial count modelling of acoustic data from arrays provides plausible and reliable estimates of koala density and, importantly, associated measures of uncertainty as well as an ability to model spatial variations in density across an array. Caution is needed when applying models to higher-density populations where home ranges overlap extensively and calls are evenly spread across the array. Implications: The results add to the opportunities of acoustic methods for wildlife, especially where monitoring of density requires cost-effective repeat surveys