The use of the Kalman filter in the automated segmentation of EIT lung images

In this paper, we present a new pipeline for the fast and accurate segmentation of impedance images of the lungs using electrical impedance tomography (EIT). EIT is an emerging, promising, non-invasive imaging modality that produces real-time, low spatial but high temporal resolution images of impedance inside a body. Recovering impedance itself constitutes a nonlinear ill-posed inverse problem, therefore the problem is usually linearized, which produces impedance-change images, rather than static impedance ones. Such images are highly blurry and fuzzy along object boundaries. We provide a mathematical reasoning behind the high suitability of the Kalman filter when it comes to segmenting and tracking conductivity changes in EIT lung images. Next, we use a two-fold approach to tackle the segmentation problem. First, we construct a global lung shape to restrict the search region of the Kalman filter. Next, we proceed with augmenting the Kalman filter by incorporating an adaptive foreground detection system to provide the boundary contours for the Kalman filter to carry out the tracking of the conductivity changes as the lungs undergo deformation in a respiratory cycle. The proposed method has been validated by using performance statistics such as misclassified area, and false positive rate, and compared to previous approaches. The results show that the proposed automated method can be a fast and reliable segmentation tool for EIT imaging

Definitions, Foundations and Associations of Physical Literacy: A Systematic Review

Background: The concept of physical literacy has stimulated increased research attention in recent years—being deployed in physical education, sport participation, and the promotion of physical activity. Independent research groups currently operationalize the construct differently. Objective The purpose of this systematic review was to conduct a systematic review of the physical literacy construct,as reflected in contemporary research literature. Methods: Five databases were searched using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for systematic reviews. Inclusion criteria were English language, peer reviewed, published by March 2016, and seeking to conceptualize physical literacy. Articles that met these criteria were analysed in relation to three core areas: properties/attributes, philosophicalfoundations and theoretical associations with other constructs. A total of 50 published articles met the inclusion criteria and were analysed qualitatively using inductive thematic analysis.Results: The thematic analysis addressed the three core areas. Under definitions, core attributes that define physical literacy were identified, as well as areas of conflict between different approaches currently being adopted. One relatively clear philosophical approach was prominent in approximately half of the papers, based on a monist/holistic ontology and phenomenological epistemology. Finally, theanalysis identified a number of theoretical associations, including health, physical activity and academic performance.Conclusions: Current literature contains different representations of the physical literacy construct. The costs and benefits of adopting an exclusive approach versus pluralism are considered. Recommendations for both researchers and practitioners focus on identifying and clearly articulating the definitions, philosophical assumptions and expected outcomes prior to evaluating the effectiveness of this emerging concept

Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries.

Globally, group B Streptococcus (GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation. This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations

Adolescent gender and ethnicity differences in physical activity perceptions and behavior

OBJECTIVES: To examine gender and ethnicity differences in adolescents\u27 physical activity (PA) behavior and perceptions. METHODS: Surveys designed to measure PA behavior and perception were completed by 175 adolescents. Gender and ethnicity differences in PA behavior were examined using chi-square tests. A two-way between groups MANOVA was used to examine perception. RESULTS: No significant differences were found between gender groups for PA. Caucasian students were more likely to be active and to perceive that PA makes their health better. Hispanics were more likely to perceive that PA requires more time than Caucasians. CONCLUSIONS: Findings suggest greater consideration be given to the ethnic orientation of PA behavior antecedents when promoting PA to adolescents

Prevalence and correlates of walking and biking to school among adolescents

Increasing the rates that our adolescents walk and bicycle to school, also called active transport to school (ATS), could increase the physical activity (PA) levels of that age group. This type of activity has been identified as a missed opportunity for PA. It is currently estimated that 15% of American youth walk or bicycle to school. These rates of ATS are lower than those of European and Asian youth. Efforts to enhance levels of non-motorized transport to school could aid in reducing obesity rates among American youth, decrease traffic congestion and attenuate emission of greenhouse gasses. The objective was to identify demographic, environmental and psychosocial predictors of ATS. A 30-questionnaire was completed by 2,692 students. Logistic regression was used to identify psychosocial, demographic and environmental predictors of ATS. Only 4.6% of students used ATS. Predictors of ATS were street connectedness (density of street intersections) and gender, (boys had higher ATS rates). Public health officials should be alert for opportunities to select sites for new schools that are in neighborhoods with well connected street systems. Interventions promoting ATS will need to target male and female students and there appears to be an opportunity to increase rates that students bicycle to school

Physical Activity Opportunity in K-12 Public School Settings: Nevada

Objectives: We examined the status of physical activity opportunity in Nevada K-12 public schools. The focus was on determining both prevalence and nature of existing programs as well as school administrators-perceived barriers to offering physical activity programs. Methods: A 15 item questionnaire was used to assess prevalence and nature of programs as well as perceived barriers. Results: Nevada school-age children do not have regular access to physical education. Excluding physical education, more than 30% of schools do not provide physical activity programming. Most existing programs are competitive sport related. In addition, as students matriculate through school, fewer program options and opportunities to participate throughout the school day are available. Lack of funds was the most frequently reported perceived barrier to offering physical activity programs. Conclusions: Opportunities to be physically active over the course of the school day are limited and as a result, hinder important national objectives for health-related outcomes