37 research outputs found

    An Exploration of the “Mimetic Aspects” of Storyline Used as a Creative and Imaginative Approach to Teaching and Learning in Teacher Education

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    Chapter 4. The aim of this study is to contribute to a comprehensive understanding of the potential mimetic aspects of The Storyline Approach (TSA)1. This study critically ex-amines how student teachers create imaginative make-believe experiences within the use of examples (props) in teaching and learning about sustainability. The analysis fol-lows the parameters set out in Willbergh’s (2011b; 2015, 2016, 2017) theory of mimetic didactics. Data were collected during a Storyline by sound recordings, and immediately after the Storyline using focus group interviews. The result of the study indicates that Storyline expands the students’ own experiences through imaginative make-believe interpretations created from 1) The making of the props: the frieze and the handheld puppets, 2) Taking on fictional roles and role-playing, 3) Applying, sharing and using each other’s knowledge, and 4) Perceiving activities as if they were pupils. This is in-terpreted as important for the students’ professional teachers’ qualification in bridging school content with competance for the future.publishedVersio

    Spatial divergence in the proportions of genes encoding toxic peptide synthesis among populations of the cyanobacterium Planktothrix in European lakes

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    It has been frequently reported that seasonal changes in toxin production by cyanobacteria are due to changes in the proportion of toxic/nontoxic genotypes in parallel to increases or decreases in population density during the seasonal cycle of bloom formation. In order to find out whether there is a relationship between the proportion of genes encoding toxic peptide synthesis and population density of Planktothrix spp. we compared the proportion of three gene regions that are indicative of the synthesis of the toxic heptapeptide microcystin (mcyB), and the bioactive peptides aeruginoside (aerB) and anabaenopeptin (apnC) in samples from 23 lakes of five European countries (n=153). The mcyB, aerB, and apnC genes occurred in 99%, 99%, and 97% of the samples, respectively, and on average comprised 60 ± 3%, 22 ± 2%, and 54 ± 4% of the total population, respectively. Although the populations differed widely in abundance (10−3–103 mm3 L−1) no dependence of the proportion of the mcyB, aerB, and apnC genes on the density of the total population was found. In contrast populations differed significantly in their average mcyB, aerB, and apnC gene proportions, with no change between prebloom and bloom conditions. These results emphasize stable population-specific differences in mcyB, aerB, and apnC proportions that are independent from seasonal influences

    Use of a Generalized Additive Model to Investigate Key Abiotic Factors Affecting Microcystin Cellular Quotas in Heavy Bloom Areas of Lake Taihu

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    Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation

    Visualizing Communication: Pattern Recognition on the Enron E-mail Corpus

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    Despite the rapid pace of computer hardware advancement in recent years, little has changed in the methodology of viewing and processing large, complicated sets of information. E-mail inboxes are an excellent example; the human brain has difficulty parsing patterns and relationships in any data represented as a raw list, and the principal axis of email (time received) is particularly unhelpful. This remains the prevailing layout, however, simply because there is too much dimensional structure to choose a single meaningful attribute of the messages to arrange by. An efficient way to overcome such a situation is through multidimensional analysis: by combining multiple features into one, we map the email onto a lower-dimensional manifold for navigation and visualization. We seek to arrange the data into distinct categories or clusters based on the reduced representation, and compare such an approach to a recent Dirichlet-based method. This project analyzes a representative subset of the approximately 500,000 emails encompassing 150 users from the Federal Energy Regulatory Commission\u27s investigation into the Enron Corporation. The research applies and compares a set of commonly used pattern recognition techniques to discover topical clusters in the corpus of unstructured text. As in the literature, each document is represented as a unigram bag-of-words feature vector on a (most-common) subset of the terms included in all messages. To perform dimensionality reduction, we apply and compare the traditional linear methods of Principal Components Analysis (PCA) and Multidimensional Scaling (MDS), using each representation to perform k-means clustering on the messages. The resulting data is further dimensionality-reduced and visualized for accessible comparison. We also create a generative Latent Dirichlet Allocation (LDA) topic model based on the unigram features, a recent innovation in the literature, and show its performance versus the dimensionality-reduction/clustering based methods

    Dynamics of freshwater cyanobacteria and their bioactive oligopeptides : - role of abiotic environmental factors and population structure

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    Cyanobakterier (=blÄgrÞnnalger) forekommer i nesten alle norske innsjÞer, og masseoppblomstringer av dem har vist seg Ä vÊre utbredt over hele verden. Et stort problem ved oppblomstringer av cyanobakterier er giftstoffene de produserer, de sÄkalte cyanotoksinene. I global sammenheng er det tallrike rapporter om dÞdsfall pÄ fugler og pattedyr, men det er ogsÄ beskrevet forgiftning av mennesker med dÞdelig utgang. Mange ulike stoffer har blitt identifisert fra cyanobakterier, deriblant bioaktive oligopeptider, men giftigheten av de fleste stoffene er ukjent. Denne avhandlingen er utfÞrt ved Norsk institutt for vannforskning og Universitetet i Oslo. MÄlet har vÊrt Ä Þke kunnskapen om cyanobakteriers forekomst, vekst og produksjon av giftige og potensielt giftige stoffer og sÊrlig sett i sammenheng med ulike miljÞfaktorer som temperatur, lys og tilgang pÄ nÊringsstoffer. I arbeidet er det benyttet innsamlede feltdata fra Steinsfjorden (en innsjÞ i Buskerud), vekstforsÞk, kjemiske analyser av vannprÞver og statistiske metoder. Steinsfjorden har et cyanobakteriesamfunn dominert av slekten Planktothrix som danner Ärlige oppblomstringer i 10-12 meters dyp. Veksten av Planktothrix foregÄr i hovedsak nÄr vannmassene i innsjÞen sirkulerer (vinter, vÄr og hÞst), men ogsÄ under stagnasjonsperioden (sommeren), og den er i hovedsak styrt av begrenset tilgang pÄ lys og ikke-optimale temperatur-forhold, mens den har nok tilgang pÄ nÊringsstoffer grunnet sin dype posisjon i vannsÞylen. VekstforsÞk viser at Planktothrix produserer bioaktive oligopeptider sÄ lenge de vokser, og at produksjonen av dem er lite pÄvirket av endringer i miljÞfaktorer. Innenfor en cyanobakterieart finnes det undergrupper av individer, kalt stammer, som produserer en unik sammensetning av bioaktive oligopeptider. Dette gjÞr at man kan gjenkjenne stammene kjemisk, og en populasjon vil oftest bestÄ av flere sÄkalte kjemotyper. Populasjonen av Planktothrix i Steinsfjorden er sammensatt av fire kjemotyper som alle produserer bioaktive oligopeptider, deriblant kjente cyanotoksiner. Analyser av vannprÞver tyder pÄ at mengdeforholdet mellom de ulike kjemotypene forandrer seg over tid og dermed ogsÄ mengden bioaktive oligopeptider per mengde Planktothrix. Ved en risikovurdering er det derfor ikke nok Ä vurdere faren kun ved hjelp av cyanobakterie mengde mÄlinger, man mÄ ogsÄ kjenne til cyanobakterie populasjonens kjemotype-sammensetning

    OvervÄking av GjersjÞen og Kolbornvannet med tillÞpsbekker 1972-2005. Med vekt pÄ resultater fra 2005 - datarapport

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    Denne rapporten presenterer detaljerte data fra undersĂžkelser i GjersjĂžen og Kolbotnvannet med bekker i perioden 1972-2005 med vekt 2005, i form av figurer, tabeller, litteratur og vedlegg som ikke er tatt med i sammendragsrapporten med samme navn,

    GjenÄpning av Kroksund. Effekter pÄ vannkvaliteten i Steinsfjorden og Tyrifjorden

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    Hensikten med prosjektet var Ă„ kvantifisere effekter av Ă„ fjerne veifyllingerne mellom Steinsfjorden og Tyrifjorden med hensyn til vannkvalitet, dette som beslutningsgrunnlag for Ă„ eventuelt Ă„pne sundet. Som metode ble det benyttet en matematisk vannkvalitetsmodell, CE-QUAL-W2. Modellen ble kalibrert/testet mot observasjoner. Deretter ble det kjĂžrt scenarier for ulike Ă„pninger av Kroksund. I fĂžlge scenariene gjelder: Åpning av Kroksund fĂžrte til redusert algevekst i overflatelagene i Steinsfjorden pĂ„ opp til 1 ”g klorofyll_a/l. Dette tilsvarer en reduksjon pĂ„ 17 %. Problemalgen Planktothrix ble betydelig redusert, noe av volumet ble erstattet med andre alger. PĂ„ dypt vann ble forskjellene mindre. Åpning pĂ„ 100 m (fjerne en fylling) reduserte omkring Ÿ av Planktothrix konsentrasjonene i forhold til 200 meters Ă„pning (fjerne to fyllinger). For totalt klorofyll ble resultatet omtrent det samme om man fjernet en eller to fyllinger. I Kroksund like utenfor/sĂžr for Ă„pningen ble vannkvaliteten i stĂžrre grad enn nĂ„ pĂ„virket av vann fra Steinsfjorden. De sentrale delene av Tyrifjorden ble ikke pĂ„virket i pĂ„viselig grad. Planktothrix ser ikke ut til Ă„ ha tilstrekkelig gode livsbetingelser i Tyrifjorden pga. lave fosforkonsentrasjoner der. Resultater fra tokt stĂžtter dette
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