15,456 research outputs found
STEM futures and practice, can we teach STEM in a more meaningful and integrated way?
Integrating Science, Technology, Engineering and Mathematics (STEM) subjects can be engaging for students, can promote problem-solving and critical thinking skills and can help build real-world connections. However, STEM has long been an area of some confusion for some educators. While they can see many of the conceptual links between the various domains of knowledge they often struggle to meaningfully integrate and simultaneously teach the content and methodologies of each these areas in a unified and effective way for their students. Essentially the question is;how can the content and processes of four disparate and yet integrated learning areas be taught at the same time? How can the integrity of each of the areas be maintained and yet be learnt in a way that is complementary? Often institutional barriers exitin schools and universities to the integration of STEM. Organizationally, at a departmental and administrative level, the teaching staff may be co-located, but when it comes to classroom practice or the teaching and learning of these areas they are usually taught very separately. They are usually taught in different kinds of spaces, in different ways (using different pedagogical approaches) and at different times. But is this the best way for students to engage with the STEM areas of learning? How can we make learning more integrated, meaningful and engaging for the students
The Role of Microenvironment Reagent Solubility on Reaction Kinetics of 4-Nitrophenol Reduction
The Role of Microenvironment Reagent Solubility on Reaction Kinetics of 4-Nitrophenol Reduction
Michael Zeevi1 with Andrew Harrison1 and Christina Tang, PhD1
1Department of Chemical and Life Science Engineering, VCU School of Engineering
Introduction: Nanoparticles are of increasing interest due to their high surface area to volume ratio, as well as that they enable fine-tuning of the reaction microenvironment. Through flash nanoprecipitation, core-shell polymer nanoreactors were formed by directed self-assembly. Using the reduction of 4-nitrophenol as a model reduction reaction, we investigated the effect of reagent solubility in the nanoreactor microenvironment’s on nanoreactor kinetics.
Methods: The standard reaction was conducted at room temperature, with a 1000-fold excess of sodium borohydride in a quartz cuvette for real-time in situ UV-Vis analysis. Reagent concentrations were varied to examine the resulting effect on the calculated reaction rate constant. Reagent solubility limits in the nanoreactor microenvironment were estimated from solubility measurements in solvents with similar Hansen solubility parameters. Ethanol was chosen to represent the hydrophilic poly(ethylene) glycol phase and chloroform was chosen to represent the hydrophobic polystyrene phase. The hydrophilic phase had a visual absorbance at nm, and thus UV-Vis spectrometry was used to determine the saturation concentration. 1H NMR analysis with chloroform-D containing an internal standard (v/v TMS 0.03%) was used to measure the reagent solubility in the hydrophobic phase.
Results: 4-nitrophenol solubility in ethanol was determined by UV-Vis spectrometry to be . The solubility in chloroform-D was determined by 1H NMR to be . When 4-nitrophenol concentration is varied independently of sodium borohydride, an inverse relationship is observed with respect to the rate constant. However, when 4-nitrophenol and sodium borohydride concentrations are varied concurrently, no change is witnessed in the rate constant above the standard reaction concentration.
Conclusions: This experiment demonstrated that the rate of reaction in polystyrene core nanoreactors is not dependent on the reagent concentrations above the standard concentration. Solubility in each phase was measured in an effort to explain this behavior. The differences in solubility observed between the hydrophobic and hydrophilic phases may serve to explain this behavior if the interior, hydrophobic phase is saturated by 4-nitrophenol at the standard concentration. Future work should include study of concentrations at lower values than the standard concentration to determine when a change in the observed rate constant occurs.https://scholarscompass.vcu.edu/uresposters/1287/thumbnail.jp
'Language is the source of misunderstandings'–impact of terminology on public perceptions of health promotion messages
Background:
The high level of premature death due to non-communicable diseases has been associated with unhealthful lifestyles, including poor diet. The effectiveness of public health strategies designed to promote health via messages focusing on food and diets depends largely on the perception of the messages by the public. The aim of this study was to explore public perceptions of language commonly used to communicate concepts linking health, food and the diet.<p></p>
Methods:
This study is a qualitative and semi-quantitative cross-sectional survey exploring public perceptions of terms used to improve eating habits within public health strategies. We recruited adults with no background in nutrition or health-care, from May to July 2013, from urban areas of varying deprivation (n = 12) in Glasgow and Edinburgh, UK. Four key prompt-terms used to convey the idea of improving health through diet were selected for testing: Healthy Eating, Eating for Health, Balanced Diet and Nutritional Balance. Consumer understanding of these terms was explored using mixed-methods, including qualitative focus groups (n = 17) and an interviewer-led word-association exercise (n = 270).<p></p>
Results:
The word-association exercise produced 1,386 individual responses from the four prompt-terms, with 130 unique responses associated with a single term. Cluster analysis revealed 16 key themes, with responses affected by prompt-term used, age, gender and socio-economic status. Healthy Eating was associated with foods considered ‘healthy’ (p <0.05); Eating for Health and Balanced Diet with negative connotations of foods to avoid (both p <0.001) and Nutritional Balance with the benefits of eating healthily (p <0.01). Focus groups revealed clear differences in perceptions: Eating for Health = positive action one takes to manage existing medical conditions, Healthy Eating = passive aspirational term associated with weight management, Balanced Diet = old fashioned, also dieting for weight loss, Nutritional Balance = maximising physical performance. Food suppliers use Healthy Eating terminology to promote weight management products. Focus group participants welcomed product reformulation to enhance food health properties as a strategy to overcome desensitisation to health-messages.<p></p>
Conclusions:
Public perceptions of messages communicating concepts linking health, food and the diet are influenced by terminology, resulting in confusion. To increase individual commitment to change eating habits in the long term, public health campaigns need strengthening, potentially by investing in tailored approaches to meet the needs of defined groups of consumers
Sports and Child Development
Despite the relevance of cognitive and non-cognitive skills for professional success, their formation is not yet fully understood. This study fills part of this gap by analyzing the effect of sports club participation, one of the most popular extra-curricular activities, on children’s skill development. Our results indicate positive effects: both cognitive skills, measured by school performance, and overall non-cognitive skills improve by 0.13 standard deviations. The results are robust when using alternative datasets as well as alternative estimation and identification strategies. The effects can be partially explained by increased physical activities replacing passive leisure activities.skill formation, non-cognitive skills, physical activity, semi-parametric estimation
Sports and Child Development
Despite the relevance of cognitive and non-cognitive skills for professional success, their formation is not yet fully understood. This study fills part of this gap by analyzing the effect of sports club participation, one of the most popular extra-curricular activities, on children's skill development. Our results indicate positive effects: both cognitive skills, measured by school performance, and overall non-cognitive skills improve by 0.13 standard deviations. The results are robust when using alternative datasets as well as alternative estimation and identification strategies. The effects can be partially explained by increased physical activities replacing passive leisure activities.skill formation, non-cognitive skills, physical activity, semi-parametric estimation
Simple interest rate rules with a role for money
The paper analyses the performance of simple interest rate rules which feature a response to noisy observations of inflation, output and money growth. The analysis is based on a small empirical model of the hybrid New Keynesian type which has been estimated on euro area data by Stracca (2007). To assess the magnitude of the measurement problems regarding the feedback variables, we draw upon the real-time data set for Germany compiled by Gerberding et al. (2004). We find that interest rate rules which include a response to money growth outperform both Taylor-type rules and speed limit policies once real-time output gap uncertainty is accounted for. One reason is that targeting money growth introduces history dependence into the policy rule which is desirable when private agents are forward-looking. The second reason is that money growth contains information on the "true" growth rate of output which can only be measured imperfectly. --Monetary policy rules,euro area,data uncertainty
The closer the sportier? Children's sport activity and their distance to sport facilities
We investigate whether the distance between the next sport facilities and children's homes matter for their sports activities inside and outside of sport clubs. Our analysis is based on a large and informative cross-section of individual data of children and their families, the so-called KIGGS data. We use a semiparametric econometric method to investigate this relationship empirically. Our results suggest that while the distance does not matter in larger towns and cities, it does matter in smaller towns and in particular on the countryside.Sport activities of children, KIGGS data, propensity score matching methods.
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