Many mathematics teachers struggle to effectively integrate information and communication technology (ICT) in their teaching and need continuous professional development programmes to improve their ...technological pedagogical content knowledge (TPACK). This article aims to identify mathematics teachers’ levels of TPACK and barriers to integrating ICT as a means to inform their continuous professional development needs. The TPACK framework of Mishra and Koehler was used as a lens for this the study. Both quantitative and qualitative research methods were utilised. Ninety-three mathematics teachers, who completed a quantitative questionnaire, reported higher levels of content, pedagogical, and pedagogical content knowledge, with comparatively lower levels of technology, technological pedagogical, and technological content knowledge. Ten of these participants also participated in semi-structured interviews and revealed six primary barriers to integrating ICT in the classroom, namely curriculum-related time constraints, technological infrastructure, impact of ICT use on the learning process, ineffective professional development, teachers’ pedagogical beliefs and poor leadership. Continuous professional development programmes addressing specific ICTintegration barriers can effect significant changes in teachers’ TPACK, which may promote better teaching and learning of mathematics.
Foundation programmes provide an alternate access route for prospective students whose prior academic results exclude direct entry to undergraduate studies. Bridging courses within foundation ...programmes address gaps in prior knowledge while developing content knowledge and requisite skills to equip students for the rigour of undergraduate degree study. This study looks for relationships between motivation and learning strategies at course commencement and the final course results of 796 purposively chosen participants across four iterative cycles (cohorts) enrolled in an algebra course within a foundation programme at a private higher education institution in South Africa. Data were collected with the motivated strategies for learning questionnaire, and cohort responses were analysed using correlational statistics. Statistically significant differences mainly were detected in the motivation subscales, and the academic performance was largely related to gender and prior mathematics syllabus. Where cohorts are similar, generic interventions designed to equip one cohort may equip others. Specific intervention strategies that target the needs of students based on the needs identified in this study may equip future students to improve their algebraic knowledge.
Objective techniques have been developed to consistently identify cloudy pixels over nonpolar regions in multispectral imager data coincident with measurements taken by the Clouds and Earth's Radiant ...Energy System (CERES) on the Tropical Rainfall Measuring Mission (TRMM), Terra, and Aqua satellites. The daytime method uses the 0.65-, 3.8-, 10.8-, and 12.0-mum channels on the TRMM Visible and Infrared Scanner (VIRS) and the Terra and Aqua MODIS. The VIRS and Terra 1.6-mum channel and the Aqua 1.38- and 2.1-mum channels are used secondarily. The primary nighttime radiances are from the 3.8-, 10.8-, and 12.0- mum channels. Significant differences were found between the VIRS and Terra 1.6-mum and the Terra and Aqua 3.8-mum channels' calibrations. Cascading threshold tests provide clear or cloudy classifications that are qualified according to confidence levels or other conditions, such as sunglint, that affect the classification. The initial infrared threshold test classifies ~43% of the pixels as clouds. The next level seeks consistency in three (two) different channels during daytime (nighttime) and accounts for roughly 40% (25%) of the pixels. The third tier uses refined thresholds to classify remaining pixels. For cloudy pixels, ~ 4% yield no retrieval when analyzed with a cloud retrieval algorithm. The techniques were applied to data between 1998 and 2006 to yield average nonpolar cloud amounts of ~ 0.60. Averages among the platforms differ by <0.01 and are comparable to surface climatological values, but roughly 0.07 less than means from two other satellite analyses, primarily as a result of missing small subpixel and thin clouds.
Many learners are unmotivated to learn mathematics due to a lack of attention, irrelevance of mathematics, low self-confidence and dissatisfaction. However, peer tutoring can afford learners ...opportunities to engage with other individuals who have overcome similar challenges in the learning of mathematics and who can motivate them to become increasingly mindful of the task at hand at their own pace in a one-on-one relationship. This article reports on Grade 12 peer tutors’ views on their role in motivating Grade 8 and Grade 9 learners to learn mathematics in relation to the four categories of learner motivation, namely attention, relevance, confidence and satisfaction (ARCS). The four categories adapted from the ARCS model of motivation were used as a lens to view and analyse the data using theoretical thematic analysis. This qualitative article utilised pre- and post-interviews as data collection instruments. Ten of the best-performing Grade 12 learners at an ex-model C school in Gauteng province in South Africa were purposively selected to participate in the research. The findings revealed that peer tutors view their role to motivate learners to learn mathematics peculiar to seven positions, which can inform future research on intervention strategies to improve mathematics performance. This article introduces research on an adapted use of the ARCS model of motivation in motivating learners to learn mathematics, which is a novel way of bringing new perspectives to research on motivation in mathematics at secondary school level.
The purpose of this study was to investigate preservice teachers’ (PSTs') beliefs about their intentions to integrate information and communication technologies (ICTs) in their future mathematics ...classrooms. The main research objective was to examine the extent to which PSTs’ beliefs predicted their intentions to integrate ICTs in their classrooms. We adopted a sequential mixed-methods design in which a survey questionnaire was the main data collection method followed by focus group and individual interviews. 147 secondary mathematics PST majors at two South African universities responded to the questionnaire. We purposefully selected eighteen of the preservice teachers for individual and focus group interviews. Quantitative results partly affirmed usefulness beliefs as the strongest predictor of attitude, which in turn was the strongest predictor of intentions to integrate mathematics teaching and learning ICTs. Although survey data showed that the influence of superiors and peers had the strongest influence on subjective norms, interview data contrastingly revealed that learners’ needs and societal expectations in the digital age pressured PSTs more to shift their professional identities. While quantitative results showed that self-efficacy beliefs had the strongest influence on PSTs’ control on ICT integration, the most recurrent self-efficacy theme from interviews was PST’s plea for training in the use of ICT tools. A wide range of ICT tools were identified as applicable to mathematics classrooms. This signified varying conceptions of which ICT tools were appropriate for mathematics teaching and learning. A recommendation is that mathematics teaching and learning ICT’s should be integrated as early as possible in initial teacher education curricula.
THE MIXED-PHASE ARCTIC CLOUD EXPERIMENT Verlinde, J.; Harrington, J. Y.; McFarquhar, G. M. ...
Bulletin of the American Meteorological Society,
02/2007, Letnik:
88, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The Mixed-Phase Arctic Cloud Experiment (M-PACE) was conducted from 27 September through 22 October 2004 over the Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research ...Facility (ACRF) on the North Slope of Alaska. The primary objectives were to collect a dataset suitable to study interactions between microphysics, dynamics, and radiative transfer in mixed-phase Arctic clouds, and to develop/evaluate cloud property retrievals from surface- and satellite-based remote sensing instruments. Observations taken during the 1977/98 Surface Heat and Energy Budget of the Arctic (SHEBA) experiment revealed that Arctic clouds frequently consist of one (or more) liquid layers precipitating ice. M-PACE sought to investigate the physical processes of these clouds by utilizing two aircraft (an in situ aircraft to characterize the microphysical properties of the clouds and a remote sensing aircraft to constraint the upwelling radiation) over the ACRF site on the North Slope of Alaska. The measurements successfully documented the microphysical structure of Arctic mixed-phase clouds, with multiple in situ profiles collected in both single- and multilayer clouds over two ground-based remote sensing sites. Liquid was found in clouds with cloud-top temperatures as cold as −30°C, with the coldest cloud-top temperature warmer than −40°C sampled by the aircraft. Remote sensing instruments suggest that ice was present in low concentrations, mostly concentrated in precipitation shafts, although there are indications of light ice precipitation present below the optically thick single-layer clouds. The prevalence of liquid down to these low temperatures potentially could be explained by the relatively low measured ice nuclei concentrations.
The National Aeronautics and Space Administration's Clouds and the Earth's Radiant Energy System (CERES) Project was designed to improve our understanding of the relationship between clouds and solar ...and longwave radiation. This is achieved using satellite broad-band instruments to map the top-of-atmosphere radiation fields with coincident data from satellite narrow-band imagers employed to retrieve the properties of clouds associated with those fields. This paper documents the CERES Edition-2 cloud property retrieval system used to analyze data from the Tropical Rainfall Measuring Mission Visible and Infrared Scanner and by the MODerate-resolution Imaging Spectrometer instruments on board the Terra and Aqua satellites covering the period 1998 through 2007. Two daytime retrieval methods are explained: the Visible Infrared Shortwave-infrared Split-window Technique for snow-free surfaces and the Shortwave-infrared Infrared Near-infrared Technique for snow or ice-covered surfaces. The Shortwave-infrared Infrared Split-window Technique is used for all surfaces at night. These methods, along with the ancillary data and empirical parameterizations of cloud thickness, are used to derive cloud boundaries, phase, optical depth, effective particle size, and condensed/frozen water path at both pixel and CERES footprint levels. Additional information is presented, detailing the potential effects of satellite calibration differences, highlighting methods to compensate for spectral differences and correct for atmospheric absorption and emissivity, and discussing known errors in the code. Because a consistent set of algorithms, auxiliary input, and calibrations across platforms are used, instrument and algorithm-induced changes in the data record are minimized. This facilitates the use of the CERES data products for studying climate-scale trends.
Infrared Spectroscopy of Resonantly Ionized (Phenol)(H2O) n Kleinermanns, K; Janzen, Ch; Spangenberg, D ...
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory,
07/1999, Letnik:
103, Številka:
27
Journal Article
Recenzirano
The infrared spectra of (phenol)(H2O) n + cluster ions (n = 1−4, 7, 8) have been recorded in the region from 2850 to 3800 cm-1. The method developed for this study (IR-PARI = infrared ...photodissociation after resonant ionization) allows sensitive IR spectroscopy of cluster ions from size-selected neutral precursors. The three-color laser scheme used for ion selection and dissociation consists of a two-color S0 → S1 → D0 ionization of a mass-selected cluster followed by IR photodissociation of the cluster ion. The IR spectra were taken by monitoring the photodissociation dip of the parent ion signal and by recording the rise of the −H2O fragment signal. The experimentally observed frequencies are compared to the results of ab initio calculations. No proton transfer is observed for the (phenol)(H2O)1,2 + clusters. In contrast to the S0 state, the structure of (phenol)(H2O)2 + turns out to be linear. In the case of the (phenol)(H2O)3,4 + clusters, linear and solvated structures are discussed. Within the solvated structures, proton transfer can occur between phenol and the water molecule, which is hydrogen-bonded to phenol. The observed fragmentation thresholds indicate proton transfer for (phenol)(H2O) n ≥ 4 + on the nanosecond time scale of our experiment. At least for the (phenol)(H2O)8 + cluster, the second solvation shell is full and a third solvation shell will be formed.
In this article I report on research intended to characterise and compare the thinking styles of Grade 10 learners studying Mathematics and those studying Mathematical Literacy in eight schools in ...the Gauteng West district in South Africa, so as to develop guidelines as to what contributes to their subject choice of either Mathematics or Mathematical Literacy in Grade 10. Both a qualitative and a quantitative design were used with three data collection methods, namely document analysis, interviews and questionnaires. Sixteen teachers participated in one-to-one interviews and 1046 Grade 10 learners completed questionnaires. The findings indicated the characteristics of learners selecting Mathematics and those selecting Mathematical Literacy as a subject and identified differences between the thinking styles of these learners. Both learners and teachers should be more aware of thinking styles in order that the learners are able to make the right subject choice. This article adds to research on the transition of Mathematics learners in the General Education and Training band to Mathematics and Mathematical Literacy in the Further Education and Training band in South Africa.
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