David F. Thompson

Misconceptions and Conceptual Changes concerning Continental Drift and Plate Tectonics among Portuguese Students Aged 16‐17

Abstract The study investigates the misconceptions of Portuguese students aged 16‐17 in an area of science education, earth science education, which is insufficiently researched. Students’ ideas of the following concepts were probed: continent, ocean, permanence of ocean basins, continental drift, the Earths magnetic field, and plates and plate motions. Interviews were carried out and a questionnaire was administered to a total of 270 students after normal specialist teaching. A teaching‐learning model was designed based on a constructivist approach which was underpinned by resources and strategies planned and trialled with an experimental group of volunteer students. The results reveal that the students held a substantial number of misconceptions. The resources and strategies designed to remediate the misconceptions proved to be effective and enjoyable in use.

Portuguese Students' Understanding at Ages 10-11 and 14-15 of the Origin and Nature of the Earth and the Development of Life

Abstract This study was initiated in an area of school science, earth science education, which has been little explored. A sample of 493 Portuguese pupils aged 10‐11 and 14‐15 (at the beginning and end of secondary schooling) was involved. The study used interviews and a written questionnaire to probe the ideas about the origin and development of earth and life which were held by pupils who had not been taught those topics, the conjecture being that pupils would have developed their own beliefs. A significant number of commonly‐held ideas were found which were independent of those relating to the scientific consensus. Using suggestions provided by existing teaching‐learning models, guidelines are developed which should help learners to challenge their homespun views and promote their own conceptual changes.

Rapid production of cyclonic spray chambers for inductively coupled plasma applications using low cost 3D printer technology

The development of low cost 3D printer technology is having a profound effect on everyday life. Over the past few years there have been many reports in the media detailing futuristic uses of this technology. Whilst the merits of these applications are clear there is an opportunity for this technology to enhance current research where a degree of fabrication is required. This work describes some initial research into the use of 3D printing for the fabrication of cyclonic spray chambers for inductively coupled plasma applications. The linearity, precision and detection limits obtained from the 3D printed chamber have been compared to a commercial model with largely positive results. Comparison between the performance of subsequent prints of the same spray chamber has also been carried out and has been shown to be highly reproducible. This work suggests that low-cost 3D printing techniques can be used as an inexpensive way to fabricate prototype spray chambers to accelerate the research in this area.

Profiling biological samples using ultra performance liquid chromatography–inductively coupled plasma–mass spectrometry (UPLC-ICP-MS) for the determination of phosphorus and sulfur-containing metabolites

In this preliminary study UPLC-ICP-MS has been utilized to profile a range of different bio-fluids and tissue extracts for sulfur and phosphorus-containing metabolites. Particular attention has been given to the livers, plasma and urine from lean and obese Zucker rats, with a view to differentiating between them based solely on their respective sulfur or phosphorus profiles and/or their total sulfur and phosphorus content. In addition, bile and tumour extracts have been analysed to observe the nature of their profiles. To the best of our knowledge this is the first time ICP-MS has been used in a non-targeted metabonomic study. Results have shown lower limits of quantification for sulfur and phosphorus methods of 0.25 and 0.15 ng on column with CVs of 14.7% and 10.9% respectively. Total phosphorus analysis of the Zucker rat aqueous liver extracts, plasma and urine has shown the pattern of phosphorus concentrations to be statistically significantly different in the lean and obese Zucker rats. Chromatographic separation of the Zucker rat organic liver extracts and plasma allowed further differentiation between the lean and obese rats using their phosphorus profiles alone. In conclusion, this preliminary study has shown the potential of UPLC-ICP-MS to quantitatively discriminate between different species biofluids, fluids and tissues based solely on their phosphorus or sulfur concentrations and/or metabolomes.

Development and validation of a NANOGold™ immunoassay for the detection of vascular endothelial growth factor (VEGF) in human serum using inductively coupled plasma mass spectrometry

This work aimed to develop and validate a NANOGold based assay, quantified using inductively coupled plasma mass spectrometry (ICP-MS), for the detection of human vascular endothelial growth factor (hVEGF) in serum. The initial assay range based on calibration standards was 62.5-2000 pg/mL with a detection limit of approximately 30 pg/mL. After validation using spiked validation controls, a quantification range between 175 and 1928 pg/mL was obtained. The inter-assay precision was between 2.3 and 18.9% with accuracy between -8.8 and -3.1%. Additional performance parameters, including dilutional linearity, matrix specificity and time-factored drift, were within +/-20%, as defined by the validation acceptance criteria for the validation of macromolecule immunoassays used within our clinical environment. Serum samples from healthy donors were analysed to determine the endogenous levels of VEGF present; these ranged from 164 to 580 pg/mL with a mean of 273 pg/mL. The intra- and inter-assay precision obtained from the healthy donor samples were 1.3-10.7% and 4.2-17.5%, respectively. This demonstration of a validated immunoassay opens further possibilities, utilising the simultaneous detection capabilities of ICP-MS for the detection of multiple analytes in a single validated immunoassay, for routine use within a clinical environment.

Phosphorus and sulfur metabonomic profiling of tissue and plasma obtained from tumour‐bearing mice using ultra‐performance liquid chromatography/inductively coupled plasma mass spectrometry

RATIONALE Metabonomic studies use complex biological samples (blood plasma/serum, tissues, etc.) that when analysed with high-performance liquid chromatography/mass spectrometry (HPLC/MS) or nuclear magnetic resonance (NMR) generate profiles that may contain many thousands of features. These profiles can be difficult to interpret with the majority of the features contributing little to the study. As such there is an argument for the development of techniques that can simplify the problem by targeting particular classes of compounds. METHODS In this study ultra-performance liquid chromatography/inductively coupled plasma mass spectrometry (UPLC/ICP-MS) was used to profile tumour tissue and plasma samples for phosphorus- and sulfur-containing metabolites. These samples were xenograft tumours (derived from breast, lung and colon cell lines) and plasma obtained from nude mice. Plasma was also obtained from non-tumour-bearing mice as a control. Due to isobaric interferences this method took advantage of the dynamic reaction cell within the ICP-MS system to react the phosphorus and sulfur ions with oxygen. The PO+ and SO+ ions were then monitored free of interferences. The total phosphorus and sulfur within each sample was also recorded using flow injection ICP-MS. A robust quality control system based on pooled sample replicate analysis was used throughout the study. RESULTS Determination of the total phosphorus and sulfur content of each sample was sufficient in itself for statistical differentiation between the majority of the cell lines analysed. Subsequent reversed-phase chromatographic profiling of the organic tumour and plasma extracts revealed the presence of a number of well-retained phosphorus-containing compounds that showed tumour-specific profiles. Reversed-phase profiling was not suitable for the sulfur-containing compounds which eluted with the solvent front. CONCLUSIONS This study has shown the potential use of UPLC/ICP-MS to differentiate between tumour cell lines, using both plasma and tumour tissue samples, based solely on metabolites that contain phosphorus or sulfur. Whilst further work is required to identify these compounds this methodology shows the ability of the described methods to provide targets for future biomarker discovery studies. Copyright

The Importance of History and Epistemology in the Designing of Earth Science Curriculum Materials for General Science Education

The value and importance of writing, trialling and using curriculum materials which incorporate an epistemological and historical dimension are illustrated with reference to the teaching and learning of what is widely recognised as the most recent revolution in scientific knowledge. This relates to the percursor ideas of continental drift and sea floor spreading and finally to a modern understanding of the cyclical workings of the shells of the outer parts of the Earth. These latter processes have become incorporated into what is now known in academia and even the media as plate tectonic theory. The events and factors relating to the ways in which scientific knowledge was gained during the course of this revolution (1840‐1975) and the degree to which it can be analysed in Khunian terms are outlined. The educational rationale for, and the desirability of, incorporating elements of this revolution and its epistemological origins into the Portuguese National Science Curriculum at ages 13‐14 and 15‐17 years, and the explanation of the ways in which this was carried out, are highlighted by reference to the four phases of a relatively novel curriculum model. Students’, teachers’ and teacher educators’ evaluations of the effectiveness of these procedures are explained.

Changes in Perceptions and Attitudes of Pre‐service Postgraduate Secondary Science Teachers: a comparative study of programmes in Israel, England and Wales

Abstract This study dealt with the development of English‐Welsh and Israeli pre‐service secondary science teachers immediately before and after their initial teacher education (ITE) courses. Data were collected through a questionnaire and interviews conducted during and at the end of courses. The main findings of the study are four‐fold: (1) Both groups possessed progressive ideas about science education before entering the programme. (2) Almost all the original significant differences between the two groups remained after the students had participated in the programmes. (3) Throughout their teaching practices, almost all students passed through a dynamic process of transformation and changed their perceptions/attitudes about science education in schools. The British students, however, developed more progressive ideas and positive attitudes of a professional kind than the Israelis. (4) The influence of university tutors was effective only whilst the students found that their ideas provided them with usefu...

Metabonomic Profiling of Chicken Eggs during Storage Using High-Performance Liquid Chromatography–Quadrupole Time-of-Flight Mass Spectrometry

Metabonomic techniques have been used to discover subtle differences in the small-molecule profiles of chicken eggs, which could help to combat fraud within the egg industry. High-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-ToF-MS) was used to obtain profiles of the small molecules present in the yolks of chicken eggs stored for different lengths of time. Statistical analysis, including the use of XCMS Online and further exploratory statistics, was able to uncover differences in the abundances of several of the small molecules found in these egg yolks. One of these small molecules was identified through the use of METLIN and MS/MS analysis as choline. A targeted study was then carried out over a longer storage period, using the same instrumentation and analytical techniques, in order to observe how the concentration of choline in egg yolk changes over a longer period of time.

Use of Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry and Metabonomic Profiling To Differentiate between Normally Slaughtered and Dead on Arrival Poultry Meat

Metabonomic profiling techniques, with established quality control methods, have been used to detect subtle metabolic differences in tissue that could aid in the discovery of fraud within the food industry. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) was utilized to acquire metabolic profiles of muscle, heart, and liver tissue from normally slaughtered and dead on arrival chickens. A workflow including XCMS Online for data processing and robust confirmatory statistics was used in order to differentiate between the two sample types. It was found that normally slaughtered and dead on arrival chicken can be differentiated based on the metabolic profile and multivariate analysis. Markers were found to be significantly different between the two sample types in all samples. With the use of the METLIN database and MS/MS analysis of chemical standards, sphingosine was identified as a marker in the muscle tissue samples which may offer potential for the detection of fraudulently processed chicken meat. The approach taken in this work has shown that it is possible to apply the described workflows to food fraud problems, with an objective of identifying key markers that could be investigated further to determine their usefulness for fraud detection.