Computer aided analysis of dental radiographic images

This paper is a result of a fruitful cooperation between the computer science and the dental diagnosis experiences. The study presents a new approach of applying computer algorithms to radiographic images of dental implantation used for bone regeneration. We focus here only on the contribution of the computer assistance to the clinical research as the periodontal therapy is beyond the scope of this paper. The proposed system is based on a pattern recognition approach, directed to recognize density changes in the intra-bony affected areas of patients. It comprises different modules with new algorithms specially designed to treat the patients’ radiographic images more accurately. The system includes digitizing, detecting the complicated region of interest (ROI), defining reference area to correct any projection discrepancy of the follow up images, and finally to extract the distinguishing features of the ROI as a basis for determining the rate of new bone density accumulation. This study is applied to two typical dental cases for a patient who received two different operations. The results are very encouraging and more accurate than traditional techniques reported before.

Radiographic arthrosis after elbow trauma : interobserver reliability

Purpose : This study measured observer variation in radiographic rating of elbow arthrosis.

Methods : Thirty-seven independent orthopedic surgeons graded the extent of elbow arthrosis in 20 consecutive sets of plain radiographs, according to the Broberg and Morrey rating system (grade 0, normal joint; grade 1, slight joint-space narrowing with minimum osteophyte formation; grade 2, moderate joint-space narrowing with moderate osteophyte formation; and grade 3, severe degenerative change with gross destruction of the joint). The kappa multirater measure (κ) was used to estimate reliability between observers, with 0 indicating no agreement above chance, and 1 indicating perfect agreement.

Results : There was fair agreement in arthrosis ratings between surgeons. Surgeons with more than 10 years of experience had greater agreement than did surgeons with less experience, and surgeons who treated more than 10 elbow fractures per year had better agreement than did those treating fewer fractures. In post hoc analyses, 2 simplified binary rating systems (eg, “none or mild” vs “moderate or severe” arthrosis) resulted in moderate agreement among observers.

Conclusions : The 4 grades of the Broberg and Morrey classification system have only fair interobserver reliability that is influenced by subspecialty and experience. Binary rating systems might be more reliable.

Effects of predator control on behaviour of an apex predator and indirect consequences for mesopredator suppression

1. Apex predators can benefit ecosystems through top–down control of mesopredators and herbivores. However, apex predators are often subject to lethal control aimed at minimizing attacks on livestock. Lethal control can affect both the abundance and behaviour of apex predators. These changes could in turn influence the abundance and behaviour of mesopredators.

2. We used remote camera surveys at nine pairs of large Australian rangeland properties, comparing properties that controlled dingoes Canis lupus dingo with properties that did not, to test the effects of predator control on dingo activity and to evaluate the responses of a mesopredator, the feral cat Felis catus.

3. Indices of dingo abundance were generally reduced on properties that practiced dingo control, in comparison with paired properties that did not, although the effect size of control was variable. Dingoes in uncontrolled populations were crepuscular, similar to major prey. In populations subject to control, dingoes became less active around dusk, and activity was concentrated in the period shortly before dawn.

4. Shifts in feral cat abundance indices between properties with and without dingo control were inversely related to corresponding shifts in indices of dingo abundance. There was also a negative relationship between predator visitation rates at individual camera stations, suggesting cats avoided areas where dingoes were locally common. Reduced activity by dingoes at dusk was associated with higher activity of cats at dusk.

5. Our results suggest that effective dingo control not only leads to higher abundance of feral cats, but allows them to optimize hunting behaviour when dingoes are less active. This double effect could amplify the impacts of dingo control on prey species selected by cats. In areas managed for conservation, stable dingo populations may thus contribute to management objectives by restricting feral cat access to prey populations.

6. Synthesis and applications. Predator control not only reduces indices of apex predator abundance but can also modify their behaviour. Hence, indicators other than abundance, such as behavioural patterns, should be considered when estimating a predator's capacity to effectively interact with lower trophic guilds. Changes to apex predator behaviour may relax limitations on the behaviour of mesopredators, providing enhanced access to resources and prey.

Spatial ecology of an apex predator over an urban to forest gradient

This research focused on predicting habitat suitability for the Powerful Owl over an urbanization gradient. Zones along the gradient provided different proportions of habitat for this species and tied in with availability of key resources. Urban environments provided limited habitat for the Powerful Owl and may potentially be acting as ecological traps.

Leadership in higher education : The normative project of the common good in conditions of globalization, Universiti Sains Malaysia (USM), and APEX in Malaysia

In this paper, the author discusses the reform agenda undertaken by UniversitiSains Malaysia (USM) to contextualise higher education reform within culturaland social theory. It is important to understand leadership in leading reformwithin a broader and more holistic fashion that takes into account localculture, politics and history. University Sains Malaysia is embarking on what isreferred to as the APEX agenda. The APEX strategy in Malaysia is an importantapproach towards achieving world-class status university institutions. The ApexUniversities will be the nation’s centres of academic distinction. Ensuring andbuilding upon the ethical authority that APEX gives USM, the challenge of leadership in USM is to engage in the forces of globalization and modernizationwhile at the same time take cognizance of the characteristics and demands ofMalaysian culture as central still to the successful mission of USM.

Markov models and network analysis reveal sex-specific differences in the space-use of a coastal apex predator

Understanding the links between external variables such as habitat and interactions with conspecifics and animal space-use is fundamental to developing effective management measures. In the marine realm, automated acoustic tracking has become a widely used method for monitoring the movement of free-ranging animals, yet researchers generally lack robust methods for analysing the resulting spatial-usage data. In this study, acoustic tracking data from male and female broadnose sevengill sharks Notorynchus cepedianus, collected in a system of coastal embayments in southeast Tasmania were analyzed to examine sex-specific differences in the sharks' coastal space-use and test novel methods for the analysis of acoustic telemetry data. Sex-specific space-use of the broadnose sevengill shark from acoustic telemetry data was analysed in two ways: The recently proposed spatial network analysis of between-receiver movements was employed to identify sex-specific space-use patterns. To include the full breadth of temporal information held in the data, movements between receivers were furthermore considered as transitions between states of a Markov chain, with the resulting transition probability matrix allowing the ranking of the relative importance of different parts of the study area. Both spatial network and Markov chain analysis revealed sex-specific preferences of different sites within the study area. The identification of priority areas differed for the methods, due to the fact that in contrast to network analysis, our Markov chain approach preserves the chronological sequence of detections and accounts for both residency periods and movements. In addition to adding to our knowledge of the ecology of a globally distributed apex predator, this study presents a promising new step towards condensing the vast amounts of information collected with acoustic tracking technology into straightforward results which are directly applicable to the management and conservation of any species that meet the assumptions of our model.