Burning a Candle in a Vessel, a Simple Experiment with a Long History

The experiment in which a candle is burned inside an inverted vessel partially immersed in water has a history of more than 2,200 years, but even nowadays it is common that students and teachers relate the change in volume of the enclosed air to its oxygen content. Contrary to what many people think, Lavoisier concluded that any change in volume in this experiment is negligible; moreover, the explanation relating oxygen consumption in the air with its change in volume is known to be wrong. In this work we briefly review the history behind the candle experiment and its relationship with some typical erroneous explanations. One of the key factors behind Lavoisier’s success was the use of experiments carefully designed to test different hypotheses. Following these steps, we performed several closed volume experiments where the candle wick was replaced by a capillary stainless steel cylinder supported and heated by a nichrome filament connected to an external power supply. Our recorded experiments are displayed as web pages, designed with the purpose that the reader can easily visualize and analyze modern versions of Lavoisier’s experiments. These experiments clearly show an initial phase of complete combustion, followed by a phase of incomplete combustion with elemental carbon or soot rising to the top of the vessel, and a final phase where the hot artificial wick only evaporates a white steam of wax that cannot ignite because no oxygen is left in the closed atmosphere. After either a complete or incomplete combustion of the oxygen, our experiments show that the final gas volume is nearly equal to the initial air volume.     

Supporting the teaching of the visual literacies in the earth and life sciences in higher education

Internationally, there has been increasing emphasis on the teaching of the academic literacies, particularly reading and writing, in higher education institutions. However, recent research is highlighting the need for more explicit teaching of multimodal forms of communication, such as the visual literacies, in undergraduate courses in a wide range of disciplines such as the sciences, engineering and architecture. The research recognises that this is an area of academic literacy teaching that has often been neglected. This article draws on the findings of a research project which set out to understand both the multimodal literacy requirements and current practices in the teaching of these literacies in the earth and life sciences at a South African university. Three key themes are discussed: learning to see like a scientist, the importance of learning by switching between and integrating different modes of representation and teaching the conventions of representation in the sciences. The conclusion proposes ways for academic developers to work with staff to develop more explicit ways of teaching the visual literacies.     

Body composition and nutritional profile of male adolescent tennis players

In this cross-sectional study, we evaluated the body composition and dietary intake of 44 adolescent tennis players. After being divided into two groups (age 10-13 years and age 14-18), the players had their weight, height, and sexual maturation assessed. Dual-energy X-ray absorptiometry was used to assess body composition. Food intake was obtained from a non-consecutive 4-day food record. The data were analysed using the Virtual Nutri v.1.0 software and compared with the present recommendations for adolescent athletes or dietary reference intakes. Body mass index and body fat for tennis practice were adequate for 89% and 71% of the tennis players respectively, regardless of age group. A calorie deficit greater than 10% of energy expenditure was observed in 32% of the sample. Fifty percent of the athletes consumed carbohydrates in accordance with recommended values. Protein and lipid intakes were above recommended values, while fibre, calcium, potassium, magnesium, and folic acid intakes were below recommendation for 98%, 80%, 100%, 100%, and 98% of the tennis players respectively. The observed nutritional deficiencies represent an additional barrier for adolescents engaged in competitive sports to achieve an optimum nutrition to maintain growth, health, and performance.     

Marketing institutional journal subscriptions to academic libraries

This paper examines different influences on the journal cancellation and selection policies of university libraries in the UK. Changing funding arrangements are outlined, followed by a discussion of varied criteria that are used during journal cancellation exercises, and how publishers can influence this process. The paper then considers changes consequent upon the advent of the electronic journal, and suggests that this, together with budget devolution and greater library liaison with academic staff, is increasing the influence of library staff in journal selection. As a result of these various trends, direct contacts between publishers and library staff are increasing.     

Moving average procedures as an additional tool for real-time analytical quality control: challenges and opportunities of implementation in small-volume medical laboratories

IntroductionMoving average (MA) is one possible way to use patient results for analytical quality control in medical laboratories. The aims of this study were to: (1) implement previously optimized MA procedures for 10 clinical chemistry analytes into the laboratory information system (LIS); (2) monitor their performance as a real-time quality control tool, and (3) define an algorithm for MA alarm management in a small-volume laboratory to suit the specific laboratory.Materials and methodsMoving average alarms were monitored and analysed over a period of 6 months on all patient results (total of 73,059) obtained for 10 clinical chemistry parameters. The optimal MA procedures were selected previously using an already described technique called the bias detection simulation method, considering the ability of bias detection the size of total allowable error as the key parameter for optimization.ResultsDuring 6 months, 17 MA alarms were registered, which is 0.023% of the total number of generated MA values. In 65% of cases, their cause was of pre-analytical origin, in 12% of analytical origin, and in 23% the cause was not found. The highest alarm rate was determined on sodium (0.10%), and the lowest on calcium and chloride.ConclusionsThis paper showed that even in a small-volume laboratory, previously optimized MA procedures could be successfully implemented in the LIS and used for continuous quality control. Review of patient results, re-analysis of samples from the stable period, analysis of internal quality control samples and assessment of the analyser malfunctions and maintenance log have been proposed for the algorithm for managing MA alarms.     

The Training Evaluation Inventory (TEI) - Evaluation of Training Design and Measurement of Training Outcomes for Predicting Training Success

Training evaluation in research and organisational contexts is vital to ensure informed decisions regarding the value of training. The present study describes the development of a valid and reliable training evaluation inventory (TEI), as it does not exist so far. The objectives were a) to construct an instrument that is theoretically and empirically founded, but at the same time applicable within typical organisational constraints, and b) to include the assessment and perception of training design as a formative evaluation aspect. Based on previous research, ten scales were constructed, covering the training outcome dimensions subjective enjoyment, perceived usefulness, perceived difficulty, subjective knowledge gain, and attitude towards training, as well as the training design dimensions problem-based learning, activation, demonstration, application, and integration. Reliabilities of the scales were satisfactory. Data from two training studies show that the training outcome dimensions were related to external training outcome measures, underlining the validity of the TEI. Two survey samples were used to predict training outcomes based on training design. Demonstration, application, and integration emerged as the most important design dimensions. The TEI is applicable in both training research projects and in organisational contexts. It can be used for formative and summative training evaluation purposes.     

Cracking the Challenge of Changing Dispositions: Changing Hearts and Minds through Stories,Narratives, and Direct Cultural Interactions

This paper reports the findings of a study that examined changes in interns’ culturally and family-responsive dispositions over the course of a 2-year early childhood teacher preparation program that prepares teachers who are willing and able to work with culturally, linguistically, and ability-diverse young children and their families. Specifically, we studied shifts in dispositions about (a) building relationships with families, (b) feeling comfortable working with children and families with diverse cultural and linguistic backgrounds, and (c) being willing to implement culturally responsive and relevant curriculum and instruction. Qualitative methodologies were employed to examine the guiding-principles paper interns wrote at the conclusion of the program. Results of the study indicate that interns perceived that their attitudes toward and beliefs about families with cultures different from their own changed over the course of the program. They attributed these changes, in part, to their engagement in activities that involved home visits and gathering families’ stories. The interns felt they gained a greater understanding of cultural diversity and changed some of their assumptions and biases as a result of spending time with families and getting to know their sociocultural context as well as their beliefs, priorities, and goals. The interns perceived that this intimate knowledge of families helped them provide culturally responsive instruction that took into account children’s diversity and promoted cultural and linguistic continuity between home and school.     

Benefits of an Intervention Focused on Oddity and Seriation

Research Findings: A total of 72 Head Start children (M age = 53.26 months, SD = 5.07) were randomly assigned to 4 conditions. Some were taught the oddity principle (choosing the object that differs from others in a group) and seriation (ordering objects on a dimension and inserting new objects into such orders), which are forms of thinking that develop naturally at about age 4. Others were taught letters or numbers or were engaged in art activities in sessions matched in frequency, timing, and extent. Toy animals were used as props in lessons that scaffolded the children's learning. Preschoolers in the cognitive group improved their cognitive skills significantly more than the others and also became better than the numbers or art groups at identifying letters, as measured by the Letters and Words scale of the Stanford Early School Achievement Test 2. This indicates that with improved oddity and seriation skills, children profited more from lessons and letter sounds offered to all children by their classroom teacher. Comparable results were demonstrated for the oddity and seriation instruction and progress in counting and adding and subtracting objects as measured by the Woodcock–Johnson III Applied Problems scale. Practice or Policy: The content and procedures embodied in this research enable children who are economically disadvantaged to make progress in learning letters and in numeracy when enrolled in preschool. Brief periods of such activities for most of the school year may be an effective supplement to lessons on letters, letter sounds, and numeracy offered in preschool curricula.