814 research outputs found

    Transit Detection in the MEarth Survey of Nearby M Dwarfs: Bridging the Clean-First, Search-Later Divide

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    In the effort to characterize the masses, radii, and atmospheres of potentially habitable exoplanets, there is an urgent need to find examples of such planets transiting nearby M dwarfs. The MEarth Project is an ongoing effort to do so, as a ground-based photometric survey designed to detect exoplanets as small as 2 Earth radii transiting mid-to-late M dwarfs within 33 pc of the Sun. Unfortunately, identifying transits of such planets in photometric monitoring is complicated both by the intrinsic stellar variability that is common among these stars and by the nocturnal cadence, atmospheric variations, and instrumental systematics that often plague Earth-bound observatories. Here we summarize the properties of MEarth data gathered so far, and we present a new framework to detect shallow exoplanet transits in wiggly and irregularly-spaced light curves. In contrast to previous methods that clean trends from light curves before searching for transits, this framework assesses the significance of individual transits simultaneously while modeling variability, systematics, and the photometric quality of individual nights. Our Method for Including Starspots and Systematics in the Marginalized Probability of a Lone Eclipse (MISS MarPLE) uses a computationally efficient semi-Bayesian approach to explore the vast probability space spanned by the many parameters of this model, naturally incorporating the uncertainties in these parameters into its evaluation of candidate events. We show how to combine individual transits processed by MISS MarPLE into periodic transiting planet candidates and compare our results to the popular Box-fitting Least Squares (BLS) method with simulations. By applying MISS MarPLE to observations from the MEarth Project, we demonstrate the utility of this framework for robustly assessing the false alarm probability of transit signals in real data. [slightly abridged]Comment: accepted to the Astronomical Journal, 21 pages, 12 figure

    Poster Introductions II--The Children’s Health and Activity Modification Program (C.H.A.M.P.): Exploring the Impact of a 4-week Lifestyle Intervention on Obese Children and Their Families

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    C.H.A.M.P., a 4-week day camp for obese children aged 8-14, was held during August 2008. The program included daily physical activity, dietary, and behavioural modification for children, and similarly-themed educational sessions for family members on weekends. The purpose of the present study was to explore the experiences of children and family members who participated in C.H.A.M.P.. Methods: This qualitative study enlisted a trained facilitator to moderate five focus groups immediately following the intervention. Children (n = 12) were allocated to 1 of 2 groups; parents (n = 17) were allocated to 1 of 3 groups. Following a semi-structured interview guide, each session was digitally recorded, transcribed verbatim, and analyzed using inductive content analysis. Results: Preliminary analysis revealed that children enjoyed participating in physical activities progressively and felt that it got easier over time. Children reported that they felt more confident in themselves and their ability to try new activities; using positive self-talk and involving their families in healthy change were emphasized. Dietary themes for children included the importance of eating balanced meals, monitoring serving sizes, and moderation. Parents reported increased confidence in parenting skills, and greater awareness of their influence on family members. Goal setting, trust, and empowerment of children in decision making were also emphasized by parents. Conclusion: This pilot study offers unique insight into the perspectives of obese children and their families. Overall, the program was well-received and impacted participants positively. Results will be discussed in terms of their implications for continued program development and future implementation. Erin Pearson is a doctoral student in the Health and Rehabilitation Sciences Program at the University of Western Ontario. Erin\u27s research interests lie in the areas of health and exercise psychology, as well as the promotion of physical activity in sedentary populations. Currently, Erin\u27s doctoral research focuses on health and wellness pertaining specifically to obesity, behaviour modification, and the use of Motivational Interviewing and Co-Active Life Coaching as health promotion tools. Erin is the Program Coordinator for the Children\u27s Health and Activity Modification Program (C.H.A.M.P.), a group-based lifestyle intervention for obese children at risk for type II diabetes and their families

    Classifying network attack scenarios using an ontology

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    This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class

    Temperament and Objectively Measured Physical Activity and Sedentary Time among Canadian Preschoolers

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    This study sought to assess the influence of preschoolers\u27 temperament on their objectively measured physical activity and sedentary time. Actical™ accelerometers were used to measure preschoolers\u27 from London, Canada\u27s (n= 216; 2.5-5. years) physical activity and sedentary levels during childcare hours (5 consecutive days; 15. s epoch). The Child Temperament Questionnaire (CTQ) was used to assess child temperament via parent/guardian report. The six subscales of the CTQ (i.e., reaction to food, soothability, attention span, activity, sociability, and emotionality) were correlated with Actical data (i.e., sedentary time, moderate-to-vigorous physical activity, and total physical activity). The five items of the activity subscale were correlated with these three measures of sedentary time and physical activity. Pearson product-moment correlation coefficients were employed for both sets of analyses. Of the correlations examined, few had an absolute value greater than 0.10, and none were statistically significant after taking multiple comparison bias into account. The results of this work might provide additional indirect support for the conclusion that the childcare environment should be a primary focus with regard to the promotion of increased physical activity and decreased sedentary time among preschoolers. Additional research is required to confirm the relationship between preschoolers\u27 temperament and levels of physical activity and sedentary time

    Kindness as an Intervention for Student Social Interaction Anxiety, Resilience, Affect, and Mood: The KISS of Kindness Study II

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    The purpose of this study was to assess the impact of deliberate acts of kindness (DAKs) plus access to a stress management booklet (intervention), compared to the booklet alone (control) on the stress-related outcomes of resilience, social interaction anxiety, affect, and mood of undergraduate and graduate students. Participants’ study-related experiences were also explored, as were the types of DAKs. This repeated-measures, randomized controlled trial included 112 students (80 undergraduate and 32 graduate) with 56 in each condition. Four previously validated scales were implemented at baseline, immediate post-intervention, and 3-months post-intervention. A linear mixed effects model was utilized with group and time entered as fixed effects. Content analysis of open-ended question responses and DAKs logs was conducted. The KISS of Kindness II had a statistically significant interaction effect on the intervention group participants’ resilience (p = 0.0099), social anxiety (p = 0.0016), and negative affect (p = 0.0033), but had no significant impact on their positive affect or mood. Intervention participants described improvements in mental wellbeing. DAKs were plentiful (1,542 DAKs, 26 types), and show promise for university-based mental health interventions

    Liposomal Encapsulation of Amoxicillin via Microfluidics with Subsequent Investigation of the Significance of PEGylated Therapeutics

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    With an increasing concern of global antimicrobial resistance, the efforts to improve the formulation of a narrowing library of therapeutic antibiotics must be confronted. The liposomal encapsulation of antibiotics using a novel and sustainable microfluidic method has been employed in this study to address this pressing issue, via a targeted, lower-dose medical approach. The study focusses upon microfluidic parameter optimisation, formulation stability, cytotoxicity, and future applications. Particle sizes of circa. 130 nm, with viable short-term (28-day) physical stability were obtained, using two different non-cytotoxic liposomal formulations, both of which displayed suitable antibacterial efficacy. The microfluidic method allowed for high encapsulation efficiencies (≈77 %) and the subsequent in vitro release profile suggested high limits of antibiotic dissociation from the nanovessels, achieving 90% release within 72 h. In addition to the experimental data, the growing use of poly(ethylene) glycol (PEG) within lipid-based formulations is discussed in relation to anti-PEG antibodies, highlighting the key pharmacological differences between PEGylated and non-PEGylated formulations and their respective advantages and drawbacks. It's surmised that in the case of the formulations used in this study, the addition of PEG upon the liposomal membrane would still be a beneficial feature to possess owing to beneficial features such as stability, antibiotic efficacy and the capacity to further modify the liposomal membrane.</p

    Comparing the nutrition environment and practices of home- and centre-based child-care facilities

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    Objective To assess and compare the nutrition environment and practices (as they relate to pre-schoolers) of centre- and home-based child-care facilities. Design Using a cross-sectional study design, nineteen child-care facilities (ten centre-based, nine home-based) were assessed for one full day using the Environment and Policy Assessment and Observation (EPAO) tool (consisting of a day-long observation/review of the nutrition environment, practices and related documents). Specifically, eight nutrition-related subscales were considered. Setting Child-care facilities in London, Ontario, Canada. Subjects Child-care facilities were recruited through directors at centre-based programmes and the providers of home-based programmes. Results The mean total nutrition environment EPAO scores for centre- and home-based facilities were 12·3 (sd 1·94) and 10·8 (sd 0·78) out of 20 (where a higher score indicates a more supportive environment with regard to nutrition), respectively. The difference between the total nutrition environment EPAO score for centre- and home-based facilities was approaching significance (P=0·055). For both types of facilities, the highest nutrition subscale score (out of 20) was achieved in the staff behaviours domain (centre mean=17·4; home mean=17·0) and the lowest was in the nutrition training and education domain (centre mean=3·6; home mean=2·0). Conclusions Additional research is needed to confirm these findings. In order to better support child-care staff and enhance the overall nutrition environment in child care, modifications to food practices could be adopted. Specifically, the nutritional quality of foods/beverages provided to pre-schoolers could be improved, nutrition-related training for child-care staff could be provided, and a nutrition curriculum could be created to educate pre-schoolers about healthy food choices

    Environmental influences on preschoolers\u27 physical activity levels in various early-learning facilities

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    Purpose: This study aimed to: (a) compare the physical activity (PA) levels (i.e., moderateto- vigorous PA [MVPA] and total PA [TPA]) of preschoolers in 3 different early-learning environments (center-based childcare, home-based childcare, and full-day kindergarten [FDK]); and (b) assess which characteristics (e.g., play equipment, policies, etc.) of these settings influenced preschoolers\u27 PA. Method: Twenty-seven facilities (9 centers, 10 homes, and 8 FDK) participated in this study. Participants (aged 2.5-5 years; n =? 297) were fitted with Acticale accelerometers for 5 consecutive days during childcare/school hours to assess their PA. The Environment and Policy Assessment and Observation (EPAO) tool was used to objectively examine the PA environment of all participating facilities. Finally, demographic questionnaires were administered to preschoolers\u27 parents/guardians. Results: Preschoolers in FDK accumulated significantly more MVPA (p , .05; 3.33 min/hr) than those in center- (1.58 min/hr) and home-based (1.75 min/hr) childcare, and they accumulated significantly more TPA (p , .05; 20.31 min/hr) than those in center-based childcare (18.36 min/hr). For FDK, the Active Opportunities, Sedentary Opportunities, Sedentary Environment, and Fixed Play Environment subscales of the EPAO significantly impacted both MVPA and TPA. For center-based childcare, only the Sedentary Environment subscale was found to impact MVPA and TPA. No subscales influenced children\u27s MVPA or TPA in home-based childcare. Conclusions: This research underscores the need to encourage/support preschoolers\u27 active behaviors in early-learning settings, particularly for those in center- and home-based childcare. Furthermore, this article highlights environmental and staff characteristics on which future PA programming should focus
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