Influence of Process Parameters on Chlorinated Biocide Decontamination by li-CO2 on Artificially Contaminated Model Materials

ABSTRACT

Previously, heavy use of biocides for the treatment of objects made of organic materials in museum collections (e.g. ethnographic, historical collections) was very common. Now suitable decontamination methods/technologies are being sought. A decontamination treatment by li-CO₂ was optimized that considered the specific requirements of museum objects. The treatment was tested on model materials artificially contaminated with biocide solutions containing dichlorodiphenyltrichloroethane (DDT), pentachlorophenol (PCP), lindane, and permethrin or cypermethrin. High decontamination was achieved for DDT, lindane, PCP, and permethrin on artificially biocide loaded wool and wood model materials. Optimal process parameter settings for li-CO₂ decontamination include a single 30?min cycle for woolen materials and three sequential 30?min cycles each for wood. These methods allow a reduction of at least 90% of all biocides for wool and between 70% and 85% for wood. Decontamination of the latter was more effective for less polar biocides as DDT and permethrin. Despite a significant improvement in decontamination for wood using co-solvents such as acetone, ethanol, and methyl tertiary-butyl ether (MTBE), their use is not recommended due to the increased risk of damage to the objects, in particular if a surface coating is present.     

Evaluating the effectiveness of interactive computer tutorials for an undergraduate mathematical literacy course

This article describes a study of learning when students used interactive spreadsheet‐based computer tutorials in a mathematical literacy course. It foregrounds theories relating to the role of computer technology (and specifically spreadsheets) as a mediator for learning of mathematics. It outlines the application of quantitative methods involving pre‐ and post‐testing of students, both in the computer laboratory and in the lecture sessions, and discusses factors constraining the experimental design and the usefulness of the results. There are indications that the data reveal real differences between the learning experiences in the lecture sessions and the computer laboratories. It appears that in some respects the computer tutorials were more effective in conveying the concepts than the lecture sessions were. A method of analysing and representing the data, that tracks the extent of learning of concepts through the pre‐ and post‐tests, was developed. It allows for the performance of sub‐groups of students to be examined separately. This analysis shows that simple definitions of disadvantage (such as having English as a second language) are inadequate to account for the poor performance of students in the lower quartile.     

Time Spent Gaming and Social Competence in Children: Reciprocal Effects Across Childhood

Electronic games are popular and many children spend much time on this activity. Here we investigate whether the quantity of time children spend on gaming is related to their social development, making this the first study to examine this relationship in children. We examine prospective relations between time spent gaming and social competence in a community sample of Norwegian 6 year olds (n = 873) followed up at ages 8, 10, and 12, controlling for socioeconomic status, body mass index, and time spent gaming together with friends. Results revealed that greater social competence at both 8 and 10 years predicted less gaming 2 years later and that more age-10 gaming predicted less social competence at age 12 but only among girls.     

Quality Assurance and Evaluation through Brazilian lenses: an exploration into the validity of umbrella concepts

In our present research we address the question of whether it is valid to apply the Quality Assurance and Evaluation (QAE) umbrella concept, which was formulated to explain new phenomena in European educational governance, to similar developments in Brazilian basic education. This led us to reflect on the possible pitfalls and potential strengths of using umbrella concepts as analytical tools. This article presents this exploration and its operationalisation. We confronted in-built assumptions in QAE with the contested, consensual and creative use of the notion of quality in Brazilian basic education, and looked for relationships. Our analysis shows that the Brazilian developments reiterate the relationships concerning global interconnectivity, and challenges those pertaining to conformity. We argue that the main risks of using umbrella concepts seem to concern the re-production of understandings, which frequently leads to the disregarding of deviation.     

Effects of an unsupervised pedometer-based physical activity program on daily steps of adults with moderate to severe asthma: a randomized controlled trial

Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.     

Alternating current-dielectrophoresis driven on-chip collection and chaining of green microalgae in freshwaters

The capability of the AC dielectrophoresis (DEP) for on-chip capture and chaining of microalgae suspended in freshwaters was evaluated. The effects of freshwater composition as well as the electric field voltage, frequency, and duration, on the dielectrophoretic response of microalga Chlamydomonas reinhardtii were characterized systematically. Highest efficiency of cell alignment in one-dimensional arrays, determined by the percentage of cells in chain and the chain length, was obtained at AC-field of 20 V mm⁻¹ and 1 kHz applied for 600 s. The DEP response and cell alignment of C. reinhardtii in water sampled from lake, pond, and river, as well as model media were affected by the chemical composition of the media. In the model media, the efficiency of DEP chaining was negatively correlated to the conductivity of the cell suspensions, being higher in suspensions with low conductivity. The cells suspended in freshwaters, however, showed anomalously high chaining at long exposure times. High concentrations of nitrate and dissolved organic matter decrease cell chaining efficiency, while phosphate and citrate concentrations increase it and favor formation of longer chains. Importantly, the application of AC-field had no effect on algal autofluorescence, cell membrane damage, or oxidative stress damages in C. reinhardtii.     

Acute intraocular pressure changes during isometric exercise and recovery: The influence of exercise type and intensity,and participant´s sex

ABSTRACT

We assessed the intraocular pressure (IOP) behaviour during a 1-minute period of isometric physical effort and the immediate 1-minute of recovery in the mid-thigh clean pull and squat exercises at three different intensities. Twenty physically active individuals performed the isometric mid-thigh clean pull and squat exercises at three intensities (0% [low-intensity], 25% [medium-intensity] and 50% [high-intensity] of the maximum isometric force). IOP was semi-continuously measured by rebound tonometry. There was a statistically significant effect of exercise intensity on IOP (p < 0.001, ?_p² = 0.416), observing that IOP increments were positively associated with exercise intensity. The mid-thigh clean pull and squat exercises did not demonstrate differences (p = 0.510), and also, no differences were observed between men and women (p = 0.683). The IOP changes during the isometric physical effort showed a positive linear behaviour in all conditions (r = 0.70 to 0.96). IOP returned to baseline levels after 8 seconds of recovery. Our data showed a progressive and instantaneous IOP increment during isometric exercise, which was positively associated with exercise intensity. IOP changes were independent on the type of exercise and participant´s sex. After exercise, IOP rapidly (≈ 8 seconds) returned to baseline levels.     

The relevance of innovative school architecture for school principals

In many cases, innovative forms of learning require innovative concepts of using space in school. However, so far there has been a lack of research concerning the perspectives of school principals as important stakeholders in the adoption of alternative school architecture. The present study examines the importance of alternative school architecture in a sample of 1164 principals (56% females, mean-age 52.7 years) in Austria. An online questionnaire was conducted, containing questions about the school building, innovative forms of learning, and principals’ level of information, perceptions, and thoughts on the relevance of school architecture, as well as their motivation and self-efficacy. Results showed that principals are aware of the advantages of certain architectural elements, although these elements have been implemented in only a few schools. A high proportion of respondents report a lack of information about configurations of space that go beyond the traditional corridor-scheme. We conclude that although principals are in general open for the alternative configuration of space further efforts have to be made to overcome the obstacles that prevent principals from launching new concepts of using space, which are a lack of competitive resources and knowledge as well as an inadequate professional network.     

Implications of academic literacies research for knowledge making and curriculum design

This article explores the issue of what academic literacies research can bring to the study of knowledge and curriculum in higher education from a theoretical perspective and by means of illustrations from a work in progress academic literacies research project in the natural sciences. It argues that reading and writing are central to the process of learning in any discipline and that discipline specialists need to take this into consideration when planning their curricula. It also considers what knowledge means in the context of academic literacies research and how this conception of knowledge may differ from the knowledge structures researchers’ concern with knowledge as an object with its own properties. It comes to the conclusion that academic literacies research with its ethnographic-type exploration of social practice and theorisations of knowledge in the knowledge structures research can complement one another because each field of enquiry brings a lens that the other lacks.