Usability and Usage of Interactive Features in an Online Ebook for CS Teachers

There are too few secondary school computing teachers to meet international needs for growing secondary school computing education. Our group has created an ebook to help prepare secondary teachers to teach the programming and big data concepts in the new AP Computer Science Principles course. The ebook was designed using principles from educational psychology, specifically worked examples and cognitive load. The ebook interleaves worked examples and interactive practice activities, which we believe will lead to more efficient and effective learning than more typical approaches to learning programming. This paper reports the results from initial studies of our ebook. First, we conducted a usability study comparing three different ebook platforms. Next, we conducted a study of teacher use of the ebook. Ten teachers worked through the first eight chapters of the ebook at their own pace. Five of the ten teachers completed the first eight chapters which is a 50% completion rate. Significantly, teachers who used more of the interactive features in the ebook did better on the post-tests and reported higher confidence in their ability to teach the material than teachers who used few of the interactive features

An atmospheric perspective on North American carbon dioxide exchange: CarbonTracker

We present an estimate of net CO2 exchange between the terrestrial biosphere and the atmosphere across North America for every week in the period 2000 through 2005. This estimate is derived from a set of 28,000 CO2 mole fraction observations in the global atmosphere that are fed into a state-of-the-art data assimilation system for CO2 called CarbonTracker. By design, the surface fluxes produced in CarbonTracker are consistent with the recent history of CO2 in the atmosphere and provide constraints on the net carbon flux independent from national inventories derived from accounting efforts. We find the North American terrestrial biosphere to have absorbed –0.65 PgC/yr (1 petagram = 10^15 g; negative signs are used for carbon sinks) averaged over the period studied, partly offsetting the estimated 1.85 PgC/yr release by fossil fuel burning and cement manufacturing. Uncertainty on this estimate is derived from a set of sensitivity experiments and places the sink within a range of –0.4 to –1.0 PgC/yr. The estimated sink is located mainly in the deciduous forests along the East Coast (32%) and the boreal coniferous forests (22%). Terrestrial uptake fell to –0.32 PgC/yr during the large-scale drought of 2002, suggesting sensitivity of the contemporary carbon sinks to climate extremes. CarbonTracker results are in excellent agreement with a wide collection of carbon inventories that form the basis of the first North American State of the Carbon Cycle Report (SOCCR), to be released in 2007. All CarbonTracker results are freely available at http://carbontracker.noaa.gov

Social physique anxiety and physical activity in early adolescent girls : the influence of maturation and physical activity motives

This study considered the influence of maturation on social physique anxiety (SPA), the relationship between SPA and current and future physical activity (PA) levels and the influence of motives for physical activity on this relationship in early adolescent girls (n=162; mean age=11.80±0.33 years). Participants completed the Pubertal Development Scale, the modified Social Physique Anxiety Scale and the Motives for Physical Activity Scale at baseline and the Physical Activity Questionnaire for Older Children at baseline and 6 months later. The girls became less active across the 6 months and girls in the early stages of maturation had significantly lower SPA than the girls in the middle and late stages of maturation. SPA was not related to current or future physical activity in the sample as a whole. Cluster analysis identified four groups with different motive profiles and the High Appearance and Fitness group demonstrated a moderate negative relationship between SPA and PA at phase 1, whereas the other groups did not. These findings indicate that SPA may increase with maturation and the relationship between SPA and PA is dependent on reasons for being active. For girls who are motivated to be active primarily by body-related reasons SPA is likely to lead to lower levels of PA

A grounded theory of how social support influences physical activity in adolescent girls

Purpose: Adolescent girls are not sufficiently active to achieve health benefits. Social support from friends and family has been positively associated with physical activity in adolescent girls; however it is unclear how social support influences physical activity behaviour. This study aimed to develop a grounded theory of how social support influences physical activity in adolescent girls. Methods: A qualitative, constructivist grounded theory approach was adopted. Individual interviews explored adolescent girls’ perspectives of how significant others’ influenced their physical activity through providing social support, and through modelling physical activity. Results: Participants perceived social support to influence physical activity behaviour through performance improvements, self-efficacy, enjoyment, motivation and by enabling physical activity. Improvements in performance and self-efficacy were also linked to motivation to be active. Girls perceived modelling to influence behaviour through providing opportunities for them to be physically active, and by inspiring them to be active. Conclusion: The grounded theory outlines adolescent girls’ perceptions of how significant others influence their physical activity and provides a framework for future research examining the role of social support on physical activity

Approaching the low-temperature limit in nucleation and two-dimensional growth of fcc (100) metal films Ag/Ag(100)

We analyze the formation of two-dimensional Ag islands following deposition of about 0.1 ML of Ag on Ag(100) over a temperature regime ranging from classical nucleation and growth behavior to almost immobile adatoms, from 300 to 125 K. Particular emphasis is placed on the post-deposition dynamics at the lower end of the temperature range, where the saturation island density is not reached at the end of the deposition, and nucleation and aggregation processes continue with adatoms from the remaining adatom gas. Our analysis combines VT scanning tunneling microscopy experiments with kinetic Monte Carlo simulation of appropriate atomistic models. The only adjustable parameters in the model are the terrace diffusion barrier and prefactor, which can be determined from island density behavior near room temperature. Other processes such as rapid edge diffusion, and “easy” nucleation and aggregation of diagonally adjacent adatoms, are treated as instantaneous. The model excellently reproduces all aspects of behavior at low temperatures, demonstrating that nucleation and growth processes can be described in one consistent scheme, down to the regime of almost immobile adatoms

Mass-radius relationships for exoplanets

For planets other than Earth, interpretation of the composition and structure depends largely on comparing the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation which relies heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We lay out a method for deriving and testing equations of state, and deduce mass-radius and mass-pressure relations for key materials whose equation of state is reasonably well established, and for differentiated Fe/rock. We find that variations in the equation of state, such as may arise when extrapolating from low pressure data, can have significant effects on predicted mass- radius relations, and on planetary pressure profiles. The relations are compared with the observed masses and radii of planets and exoplanets. Kepler-10b is apparently 'Earth- like,' likely with a proportionately larger core than Earth's, nominally 2/3 of the mass of the planet. CoRoT-7b is consistent with a rocky mantle over an Fe-based core which is likely to be proportionately smaller than Earth's. GJ 1214b lies between the mass-radius curves for H2O and CH4, suggesting an 'icy' composition with a relatively large core or a relatively large proportion of H2O. CoRoT-2b is less dense than the hydrogen relation, which could be explained by an anomalously high degree of heating or by higher than assumed atmospheric opacity. HAT-P-2b is slightly denser than the mass-radius relation for hydrogen, suggesting the presence of a significant amount of matter of higher atomic number. CoRoT-3b lies close to the hydrogen relation. The pressure at the center of Kepler-10b is 1.5+1.2-1.0 TPa. The central pressure in CoRoT-7b is probably close to 0.8TPa, though may be up to 2TPa.Comment: Added more recent exoplanets. Tidied text and references. Added extra "rock" compositions. Responded to referee comment

Assessing free-living physical activity using accelerometry : practical issues for researchers and practitioners

Physical activity is an integral component of a healthy lifestyle, with relationships documented between physical activity, chronic diseases, and disease risk factors. There is increasing concern that many people are not sufficiently active to benefit their health. Consequently, there is a need to determine the prevalence of physical activity engagement, identify active and inactive segments of the population, and evaluate the effectiveness of interventions. The aim of the present study was to identify and explain a number of methodological and decision-making processes associated with accelerometry, which is the most commonly used objective measure of physical activity in child and adult research.Specifically, this review addresses:(a) pre-data collection decisions,(b) data collection procedures,(c) processing of accelerometer data, and(d) outcome variables in relation to the research questions posed.An appraisal of the literature is provided to help researchers and practitioners begin field-based research, with recommendations offered for best practice. In addition, issues that require further investigation are identified and discussed to inform researchers and practitioners of the surrounding debates.Overall, the review is intended as a starting point for field-based physical activity research using accelerometers and as an introduction to key issues that should be considered and are likely to be encountered at this time.<br /

The relationship between chiropractor required and current level of business knowledge

Background: Chiropractors frequently practice within health care systems requiring the business acumen of an entrepreneur. However, some chiropractors do not know the relationship between the level of business knowledge required for practice success and their current level of business knowledge. The purpose of this quantitative study was to examine the relationship between chiropractors’ perceived level of business knowledge required and their perceived level of current business knowledge. Methods: Two hundred and seventy-four participants completed an online survey (Health Care Training and Education Needs Survey) which included eight key business items. Participants rated the level of perceived business knowledge required (Part I) and their current perceived level of knowledge (Part II) for the same eight items. Data was collected from November 27, 2013 to December 18, 2013. Data were analyzed using Spearman’s ranked correlation to determine the statistically significant relationships for the perceived level of knowledge required and the perceived current level of knowledge for each of the paired eight items from Parts I and II of the survey. Wilcoxon Signed Ranks Tests were performed to determine the statistical difference between the paired items. Results: The results of Spearman’s correlation testing indicated a statistically significant (p < 0.01) positive correlation for the perceived level of knowledge required and perceived current level of knowledge for six variables: (a) organizational behavior, (b) strategic management, (c) marketing, (d) legal and ethical, (e) managerial decisions, and (f) operations. Wilcoxon Signed Ranks testing indicated a significant difference for three paired items: strategic management; marketing and; legal and ethical. The results suggest that relationships exist for the majority of business items (6 of 8) however a statistically difference was demonstrated in only three of the paired business items. Conclusion: The implications of this study for social change include the potential to improve chiropractors’ business knowledge and skills, enable practice success, enhance health services delivery and positively influence the profession as a viable career.https://doi.org/10.1186/s12998-017-0134-

Points in Mental Space: an Interdisciplinary Study of Imagery in Movement Creation

As part of a programme of research that is developing tools to enhance choreographic practice, an interdisciplinary team of cognitive scientists, neuroscientists and dance professionals collaborated on two studies examining the mental representations used to support movement creation. We studied choreographer Wayne McGregor’s approach to movement creation through tasking, in which he asks dancers to create movement in response to task instructions that require a great deal of mental imagery and decision making. In our first experiment, we used experience sampling methods (self-report scales and reports about the current focus of thought) with the full company of Wayne McGregor | Random Dance to describe what the dancers report thinking about while creating movement, and to establish how their experiences change as a function of different task conditions. In particular, we contrasted a conventional ‘active’ condition (where dancers are free to move around) with a ‘static’ condition (where they have to create movement mentally, without moving), because all neuroimaging studies of dance require participants to lie motionless within a scanner. We adapted the static mode from Experiment 1 for the neuroimaging session in Experiment 2. Here we recorded the brain activity of an experienced dancer from Wayne McGregor | Random Dance while she mentally undertook movement creation tasks similar to those used in our experience sampling experiment. Both studies involved imagery tasks of a primarily spatial-praxic nature (involving an imagined object or volume that could be approached and manipulated) and imagery that focused on content invoking emotional narratives. In the first study, the dancers’ awareness was focused more than they had anticipated upon conceptual rather than physical or bodily aspects. The very act of reflecting on, and categorising, their experiences provided the dancers with insights about their mental habits during innovative movement creation. Such insights provide conditions under which habits can be recognised and then altered to adopt alternative points in mental space from which to create movement material. Providing the dancers and McGregor with a means to communicate more productively about the properties of the task-based instructions has been acknowledged by the company to be of clear benefit and a useful addition to their working process. In the second study we assessed the feasibility of using fMRI to study the neural underpinnings of choreographing movement tasks. The experiment enabled us to compare brain activity in imagery and movement creation. The data raise some key questions Points in Mental Space 3 concerning the mental context in which such thinking occurs and, given the clear limitations of the current fMRI and experience sampling work, how future research might usefully be directed. Taken together, these two exploratory studies indicate that the experiential and neural attributes of imagery during movement creation are open to systematic investigation: innovative movement creation can start from alternative points in mental, as well as physical, space. This enables us to look forward to establishing with greater precision how tasks that challenge dancers in different ways may affect mental and neural processes and how variation in imagery use across dancers might contribute to the variety of movement creation that they produce. Notably, the act of reflecting on the experience of movement creation also offers some practical leverage to help dancers develop a wider range of strategies for innovation. These findings are being used to contribute to further work informing the development of personal, notebook-like, Choreographic Thinking Tools