Tracking of physical activity in young children

The purpose of this study was to determine whether physical activity behavior tracks during early childhood. Forty-seven children (22 males, 25 females) aged 3-4 yr at the beginning of the study were followed over a 3-yr period. Heart rates were measured at least 2 and up to 4 d . yr(-1) with a Quantum XL Telemetry heart rate monitor. Physical activity was quantified as the percentage of observed minutes between 3:00 and 6:00 p.m. during which heart rate was 50% or more above individual resting heart rate (PAHR-50 Index). Tracking of physical activity was analyzed using Pearson and Spearman correlations. Yearly PAHR-50 index tertiles were created and examined for percent agreement and Cohen's kappa. Repeated measures ANOVA was used to calculate the intraclass correlation coefficient across the 3 yr of the study. Spearman rank order correlations ranged from 0.57 to 0.66 (P < 0.0001). Percent agreement ranged from 49% to 62%. The intraclass R for the 3 yr was 0.81. It was concluded that physical activity behavior tends to track during early childhood.

Tensor-based item recommendation using probabilistic ranking in social tagging systems

A common problem with the use of tensor modeling in generating quality recommendations for large datasets is scalability. In this paper, we propose the Tensor-based Recommendation using Probabilistic Ranking method that generates the reconstructed tensor using block-striped parallel matrix multiplication and then probabilistically calculates the preferences of user to rank the recommended items. Empirical analysis on two real-world datasets shows that the proposed method is scalable for large tensor datasets and is able to outperform the benchmarking methods in terms of accuracy.

University of Glasgow at ImageCLEFPhoto 2009 : optimising similarity and diversity in image retrieval

In this paper we describe the approaches adopted to generate the runs submitted to ImageCLEFPhoto 2009 with an aim to promote document diversity in the rankings. Four of our runs are text based approaches that employ textual statistics extracted from the captions of images, i.e. MMR [1] as a state of the art method for result diversification, two approaches that combine relevance information and clustering techniques, and an instantiation of Quantum Probability Ranking Principle. The fifth run exploits visual features of the provided images to re-rank the initial results by means of Factor Analysis. The results reveal that our methods based on only text captions consistently improve the performance of the respective baselines, while the approach that combines visual features with textual statistics shows lower levels of improvements.

Encouragement of physical activity for weight loss may lead to negative psychological outcomes among girls

PURPOSE To examine correlates and consequences of parents' encouragement of girls' physical activity (PA) for weight loss (ENCLOSS). METHODS Data were collected for 181 girls, mothers and fathers when girls were 9, 11, and 13 years old. Mothers and fathers completed a self-report questionnaire of ENCLOSS (e.g., “I have talked to my daughter about how to exercise to lose weight”). Correlates of ENCLOSS that were assessed include girls' Body Mass Index (BMI) z-score and parents' modeling of and logistic support for PA. Dependent variables assessed at age 13 include girls' self-reported and objectively-measured PA, enjoyment of physical activity, and weight concerns. Associations between ENCLOSS, girls' BMI, and parent's support for PA were assessed using spearman rank correlations. To examine links between ENCLOSS and the outcome variables, scores for ENCLOSS were divided into tertiles at each age. Three groups were created including girls who were in the highest tertile at each age (high ENCLOSS), girls who were in the lowest tertile at each age (low ENCLOSS), and girls who varied in their tertile ranking (mid ENCLOSS). Group differences in the outcome variables were assessed using regression analysis (referent group: low ENCLOSS), controlling for girls' BMI and the outcome variable at age 9. RESULTS Girls' with higher BMI had mothers and fathers who reported higher ENCLOSS (r = .61-. 69, p<. 0001). Parents'reports of ENCLOSS were not associated with modeling of or logistic support for PA. Girls in the high ENCLOSS group reported significantly lower enjoyment of PA and higher weight concerns at age 13, independent of covariates. No differences in PA were noted. CONCLUSION Parents who encourage their daughters to be active for weight loss do not model PA or facilitate girls' PA. Persistent encouragement of PA for weight loss may lead to low enjoyment of PA and higher weight concerns among adolescent girls.

STI-GMaS : an open-source environment for simulation of sexually-transmitted infections

Background Sexually-transmitted pathogens often have severe reproductive health implications if treatment is delayed or absent, especially in females. The complex processes of disease progression, namely replication and ascension of the infection through the genital tract, span both extracellular and intracellular physiological scales, and in females can vary over the distinct phases of the menstrual cycle. The complexity of these processes, coupled with the common impossibility of obtaining comprehensive and sequential clinical data from individual human patients, makes mathematical and computational modelling valuable tools in developing our understanding of the infection, with a view to identifying new interventions. While many within-host models of sexually-transmitted infections (STIs) are available in existing literature, these models are difficult to deploy in clinical/experimental settings since simulations often require complex computational approaches. Results We present STI-GMaS (Sexually-Transmitted Infections – Graphical Modelling and Simulation), an environment for simulation of STI models, with a view to stimulating the uptake of these models within the laboratory or clinic. The software currently focuses upon the representative case-study of Chlamydia trachomatis, the most common sexually-transmitted bacterial pathogen of humans. Here, we demonstrate the use of a hybrid PDE–cellular automata model for simulation of a hypothetical Chlamydia vaccination, demonstrating the effect of a vaccine-induced antibody in preventing the infection from ascending to above the cervix. This example illustrates the ease with which existing models can be adapted to describe new studies, and its careful parameterisation within STI-GMaS facilitates future tuning to experimental data as they arise. Conclusions STI-GMaS represents the first software designed explicitly for in-silico simulation of STI models by non-theoreticians, thus presenting a novel route to bridging the gap between computational and clinical/experimental disciplines. With the propensity for model reuse and extension, there is much scope within STI-GMaS to allow clinical and experimental studies to inform model inputs and drive future model development. Many of the modelling paradigms and software design principles deployed to date transfer readily to other STIs, both bacterial and viral; forthcoming releases of STI-GMaS will extend the software to incorporate a more diverse range of infections.

Integrating understandability in the evaluation of consumer health search engines

In this paper we propose a method that integrates the no- tion of understandability, as a factor of document relevance, into the evaluation of information retrieval systems for con- sumer health search. We consider the gain-discount evaluation framework (RBP, nDCG, ERR) and propose two understandability-based variants (uRBP) of rank biased precision, characterised by an estimation of understandability based on document readability and by different models of how readability influences user understanding of document content. The proposed uRBP measures are empirically contrasted to RBP by comparing system rankings obtained with each measure. The findings suggest that considering understandability along with topicality in the evaluation of in- formation retrieval systems lead to different claims about systems effectiveness than considering topicality alone.

Accelerometer based performance assessment of basic routines in classical ballet

Classical ballet requires dancers to exercise significant muscle control and strength both while stationary and when moving. Following the Royal Academy of Dance (RAD) syllabus, 8 male and 27 female dancers (aged 20.2 + 1.9 yr) in a fulltime university undergraduate dance training program were asked to stand in first position for 10 seconds and then perform 10 repeats of a demi-plié exercise to a counted rhythm. Accelerometer records from the wrist, sacrum, knee and ankle were compared with the numerical scores from a professional dance instructor. The sacrum mounted sensor detected lateral tilts of the torso in dances with lower scores (Spearman’s rank correlation coefficient r = -0.64, p < 0.005). The RMS acceleration amplitude of wrist mounted sensor was linearly correlated to the movement scores (Spearman’s rank correlation coefficient r = 0.63, p < 0.005). The application of sacrum and wrist mounted sensors for biofeedback during dance training is a realistic, low cost option.

Osteoimmunomodulatory properties of magnesium scaffolds coated with β-tricalcium phosphate

The osteoimmunomodulatory property of bone biomaterials is a vital property determining the in vivo fate of the implants. Endowing bone biomaterials with favorable osteoimmunomodulatory properties is of great importance in triggering desired immune response and thus supports the bone healing process. Magnesium (Mg) has been recognized as a revolutionary metal for applications in orthopedics due to it being biodegradable, biocompatible, and having osteoconductive properties. However, Mg's high rate of degradation leads to an excessive inflammatory response and this has restricted its application in bone tissue engineering. In this study, β-tricalcium phosphate (β-TCP) was used to coat Mg scaffolds in an effort to modulate the detrimental osteoimmunomodulatory properties of Mg scaffolds, due to the reported favorable osteoimmunomodulatory properties of β-TCP. It was noted that macrophages switched to the M2 extreme phenotype in response to the Mg-β-TCP scaffolds, which could be due to the inhibition of the toll like receptor (TLR) signaling pathway. VEGF and BMP2 were significantly upregulated in the macrophages exposed to Mg-β-TCP scaffolds, indicating pro-osteogenic properties of macrophages in β-TCP modified Mg scaffolds. This was further demonstrated by the macrophage-mediated osteogenic differentiation of bone marrow stromal cells (BMSCs). When BMSCs were stimulated by conditioned medium from macrophages cultured on Mg-β-TCP scaffolds, osteogenic differentiation of BMSCs was significantly enhanced; whereas osteoclastogenesis was inhibited, as indicated by the downregualtion of MCSF, TRAP and inhibition of the RANKL/RANK system. These findings suggest that β-TCP coating of Mg scaffolds can modulate the scaffold's osteoimmunomodulatory properties, shift the immune microenvironment towards one that favors osteogenesis over osteoclastogenesis. Endowing bone biomaterials with favorable osteoimmunomodulatory properties can be a highly valuable strategy for the development or modification of advanced bone biomaterials.

Nutrient element-based bioceramic coatings on titanium alloy stimulating osteogenesis by inducing beneficial osteoimmmunomodulation

A paradigm shift has taken place in which bone implant materials has gone from being relatively inert to having immunomodulatory properties, indicating the importance of immune response when these materials interact with the host tissues. It has therefore become important to endow the implant materials with immunomodulatory properties favouring osteogenesis and osseointegration. Strontium, zinc and silicon are bioactive elements that have important roles in bone metabolism and that also elicit significant immune responses. In this study, Sr-, Zn- and Si-containing bioactive Sr2ZnSi2O7 (SZS) ceramic coatings on Ti–6Al–4V were successfully prepared by a plasma-spray coating method. The SZS coatings exhibited slow release of the bioactive ions with significantly higher bonding strength than hydroxyapatite (HA) coatings. SZS-coated Ti–6Al–4V elicited significant effects on the immune cells, inhibiting the release of pro-inflammatory cytokines and fibrosis-enhancing factors, while upregulating the expression of osteogenic factors of macrophages; moreover, it could also inhibit the osteoclastic activities. The RANKL/RANK pathway, which enhances osteoclastogenesis, was inhibited by the SZS coatings, whereas the osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs) was significantly enhanced by the SZS coatings/macrophages conditioned medium, probably via the activation of BMP2 pathway. SZS coatings are, therefore, a promising material for orthopaedic applications, and the strategy of manipulating the immune response by a combination of bioactive elements with controlled release has the potential to endow biomaterials with beneficial immunomodulatory properties.

Who are Australia’s information educators?

In recent years there has been considerable discussion afforded to the challenges facing the future of information education in Australia. This paper reports a study that explored the characteristics and experiences of Australia’s information educators. The study was undertaken as part of a larger project, which was designed to establish a consolidated and holistic picture of the Australian information profession, and identify how its future education could be mediated in a cohesive and sustainable manner. Sixty-nine of Australia’s information educators completed an online questionnaire that gathered data on aspects such as age, gender, rank, qualifications, work activities, and job satisfaction. The key findings from this study confirm that a number of pressing issues are confronting information educators in Australia. For example, Australia’s information educators are considerably older than that the total Australian academic workforce; over half the information educators who participated in the study are looking to retire in the next ten years; and, Australia’s information educators spend more time on service activities then other disciplines within Australia’s education system and are place a stronger importance on teaching over research. Left unaddressed these issues will have significant implications for the future of information education as well as the broader information profession. Many of the key observations drawn from this study may also have relevance to other disciplines in the Australian educational context.

Revisiting the adoption of innovative products on Australian road infrastructure projects

Construction product innovation can exert a positive influence on project and industry performance. However, guidance is scarce on product innovation diffusion for road infrastructure, in contrast to the large body of literature on the manufacturing industry. A conceptual framework is proposed to understand these processes. Advice is given to managers based on the framework and a large quantitative survey. The framework focuses on contextual characteristics that influence the decision to adopt new-to-industry product innovation, as part of a diffusion process. Case study data are interpreted within the revised framework to test its value and disaggregate the broad obstacles to innovation. A large quantitative survey was then conducted to rank the relative importance of the obstacles constraining the adoption of innovative products on road construction projects. The three most important obstacles were found to be: (1) overemphasis on up-front project costs during tender stage; (2) disagreement over who carries the risk of new product failure; and (3) adversarial contract relations. The results suggest refinements to the conceptual framework to make it a more powerful tool for categorizing and analysing construction innovation obstacles. Results also suggest well-resourced repeat interactions within complementary procurement and regulatory systems will enhance the project teams’ ability to recognize and address innovation obstacles. Further, improved relationships are expected to decrease the need for an overly conservative approach to product approval and prescriptive specifications.

Simultaneous localization and planning on multiple map hypotheses

This paper presents a novel method to rank map hypotheses by the quality of localization they afford. The highest ranked hypothesis at any moment becomes the active representation that is used to guide the robot to its goal location. A single static representation is insufficient for navigation in dynamic environments where paths can be blocked periodically, a common scenario which poses significant challenges for typical planners. In our approach we simultaneously rank multiple map hypotheses by the influence that localization in each of them has on locally accurate odometry. This is done online for the current locally accurate window by formulating a factor graph of odometry relaxed by localization constraints. Comparison of the resulting perturbed odometry of each hypothesis with the original odometry yields a score that can be used to rank map hypotheses by their utility. We deploy the proposed approach on a real robot navigating a structurally noisy office environment. The configuration of the environment is physically altered outside the robots sensory horizon during navigation tasks to demonstrate the proposed approach of hypothesis selection.

The influence of atmospheric conditions on the leakage current of ceramic insulators on the Colombian Caribbean coast

The contamination of electrical insulators is one of the major contributors to the risk of operation outages in electrical substations, especially in coastal zones with high salinity levels and atmospheric pollution. By using the measurement of leakage-currents, which is one of the main indicators of contamination in insulators, this work seeks to the determine the correlation with climatic variables, such as ambient temperature, relative humidity, solar irradiance, atmospheric pressure, and wind speed and direction. The results obtained provide an input to the behaviour of the leakage current under atmospheric conditions that are particular to the Caribbean coast of Colombia. Spearman’s rank correlation coefficients and principal component analysis are utilised to determine the significant relationships among the different variables under consideration. The necessary information for the study was obtained via historical databases of both atmospheric variables and the leakage current measured in over a period of one year in a 220-kV potential transformer insulator. We identified the influencing factors of temperature, humidity, radiation, wind speed and direction on the magnitude of the leakage current as the most relevant.

Productivity change of Nigerian insurance companies : 1994-2005

The aim of this paper is to estimate the productivity change of Nigerian insurance companies and to rank the companies analysed in the sample according to their productivity score. This benchmark exercise provides the companies analysed with a view of how their relative productivity can be upgraded. For this purpose, the non-parametric Luenberger productivity model is used. For comparative purposes, the non-parametric Luenberger-Hicks-Moorsteen productivity indicator is also used. The companies are ranked according to their total productivity for the period 1994-2005, using both models, which produce variations in the respective results. Economic implications arising from the study are derived.

Assessment of Geogenic Contaminants in Water Co-Produced with Coal Seam Gas Extraction in Queensland, Australia : Implications for Human Health Risk

Organic compounds in Australian coal seam gas produced water (CSG water) are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs) in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely these compounds leached from in situ coals. PAHs identified from wells include naphthalene, phenanthrene, chrysene and dibenz[a,h]anthracene. In addition, the likelihood of coal-derived organic compounds leaching to groundwater is assessed by undertaking toxicity leaching experiments using coal rank and water chemistry as variables. These tests suggest higher molecular weight PAHs (including benzo[a]pyrene) leach from higher rank coals, whereas lower molecular weight PAHs leach at greater concentrations from lower rank coal. Some of the identified organic compounds have carcinogenic or health risk potential, but they are unlikely to be acutely toxic at the observed concentrations which are almost negligible (largely due to the hydrophobicity of such compounds). Hence, this study will be useful to practitioners assessing CSG water related environmental and health risk.