321 research outputs found
Milk Diets, Grape Cures, and Bananas Galore: An Examination of Past and Present Wellness Culture Turned Sour
Professor Jacqueline Alnes, English - Milk Diets, Grape Cures, and Bananas Galore: An Examination of Past and Present Wellness Culture Turned Sou
Formative assessment in EFL writing: A case study of pupils´ perceptions of their feedback practice and attitudes to receiving and using feedback
Læreres tilbakemeldingspraksis på elevtekster er alltid aktuelt, og i løpet av det siste tiår har den norsk skolen hatt et særlig fokus på formativ vurdering igjennom den statlige satsingen Vurdering for Læring (Utdanningsdirektoratet, 2014). Hensikten med denne studien i engelsk fagdidaktikk har vært å se nærmere på formativ vurdering i skriftlig engelsk gjennom å studere én spesifikk tilbakemeldingspraksis. Kort sammenfattet, innebærer tilbakemeldingspraksisen at elevene får skriftlig tilbakemelding på tekstskriving, der styrker og svakheter skal presiseres innenfor tre hovedområder: språk, innhold og struktur. Sentralt i praksisen er tekstrevisjon og videre utnyttelse med utgangspunkt i den skriftlige tilbakemeldingen. Studien har benyttet et kvalitativt case- studie design, og det empiriske materialet består av dybdeintervju med åtte elever fra to engelskklasser på 10. trinn. Studiet tar utgangspunkt i hvordan elever oppfatter og opplever denne tilbakemeldingspraksisen, og undersøker hvordan elevene mener at de utnytter informasjonen de får fra de skriftlige tilbakemeldingene. Sentrale tema i tillegg til formativ vurdering er elevenes bruk av læringsstrategier og metakognisjon i læringsprosessen. Tidligere forskning innen fremmedspråksdidaktikk i Norge har i liten grad rettet fokus mot elevers bruk av informasjonen fra tilbakemeldinger, og studien bringer dermed et viktig tema til refleksjon og forbedret praksis. Resultatene av studien viser at elevene har tro på tilbakemeldingspraksisen som hjelp i læringsprosessen, men et kriterium er at tilbakemeldingene må være spesifikke. Funnene uttrykker også et behov for mer tydelighet i kommunikasjon av fremovermeldinger. Funnene presiserer behov for tydelighet ikke bare i hva man skal forbedre, men også hvordan man bør gå frem for å klare det, og elevene utrykker et ønske om økt lærerinvolvering i denne prosessen, et funn som igjen kan indikere mangler i deres metakognisjon. Studiens funn antyder at elevene har fokus på sine svakheter i arbeid med tekstrevisjon, og at de hovedsakelig bearbeider tilbakemeldinger som er relatert til det lokale tekstnivå (Hoel, 2000). Disse funnene danner grunnlag for implikasjoner for praksis med hensyn til hvordan tekstskriving og tekstrevisjon blir praktisert. Der i blant er viktigheten av tydeligere kommunikasjon mellom lærer og elever med hensyn til hva skriving og tekstrevisjon innebærer, for å sikre at elevene tilegner seg en mer helhetlig forståelse av målet med tekstrevisjon og hvordan de kan dra nytte av alle aspektene i tilbakemeldingen i videre tekstproduksjon. I tillegg antyder funnene at det er behov for økt fokus på språklæringsstrategier som et verktøy i videre utnyttelse av tilbakemeldinger og tekstskriving.Erfaringsbasert masteroppgave i undervisning med fordypning i engelskVID-MAUENGENGMAU65
The asymptotic behavior of Casimir force in the presence of compactified universal extra dimensions
The Casimir effect for parallel plates in the presence of compactified
universal extra dimensions within the frame of Kaluza-Klein theory is analyzed.
Having regularized and discussed the expressions of Casimir force in the limit,
we show that the nature of Casimir force is repulsive if the distance between
the plates is large enough and the higher-dimensional spacetime is, the greater
the value of repulsive Casimir force between plates is. The repulsive nature of
the force is not consistent with the experimental phenomena.Comment: 7 pages, 1 figur
Lemaitre-Tolman-Bondi model and accelerating expansion
I discuss the spherically symmetric but inhomogeneous Lemaitre-Tolman- Bondi
(LTB) metric, which provides an exact toy model for an inhomogeneous universe.
Since we observe light rays from the past light cone, not the expansion of the
universe, spatial variation in matter density and Hubble rate can have the same
effect on redshift as acceleration in a perfectly homogeneous universe. As a
consequence, a simple spatial variation in the Hubble rate can account for the
distant supernova data in a dust universe without any dark energy. I also
review various attempts towards a semirealistic description of the universe
based on the LTB model.Comment: Invited Review for a special Gen. Rel. Grav. issue on Dark Energy. 17
pages, 3 figure
Cosmic spherical void via coarse-graining and averaging non-spherical structures
Inhomogeneous cosmological models are able to fit cosmological observations
without dark energy under the assumption that we live close to the "center" of
a very large-scale under-dense region. Most studies fitting observations by
means of inhomogeneities also assume spherical symmetry, and thus being at (or
very near) the center may imply being located at a very special and unlikely
observation point. We argue that such spherical voids should be treated only as
a gross first approximation to configurations that follow from a suitable
smoothing out of the non-spherical part of the inhomogeneities on angular
scales. In this Letter we present a toy construction that supports the above
statement. The construction uses parts of the Szekeres model, which is
inhomogeneous and anisotropic thus it also addresses the limitations of
spherical inhomogeneities. By using the thin-shell approximation (which means
that the Israel-Darmois continuity conditions are not fulfilled between the
shells) we construct a model of evolving cosmic structures, containing several
elongated supercluster-like structures with underdense regions between them,
which altogether provides a reasonable coarse-grained description of cosmic
structures. While this configuration is not spherically symmetric, its proper
volume average yields a spherical void profile of 250 Mpc that roughly agrees
with observations. Also, by considering a non-spherical inhomogeneity, the
definition of a "center" location becomes more nuanced, and thus the
constraints placed by fitting observations on our position with respect to this
location become less restrictive.Comment: 6 pages, 5 figures, accepted for publication in Phys. Lett.
CMB anisotropies seen by an off-center observer in a spherically symmetric inhomogeneous universe
The current authors have previously shown that inhomogeneous, but spherically
symmetric universe models containing only matter can yield a very good fit to
the SNIa data and the position of the first CMB peak. In this work we examine
how far away from the center of inhomogeneity the observer can be located in
these models and still fit the data well. Furthermore, we investigate whether
such an off-center location can explain the observed alignment of the lowest
multipoles of the CMB map. We find that the observer has to be located within a
radius of 15 Mpc from the center for the induced dipole to be less than that
observed by the COBE satellite. But for such small displacements from the
center, the induced quadru- and octopoles turn out to be insufficiently large
to explain the alignment.Comment: 8 pages (REVTeX4), 7 figures; v2: minor changes, matches published
versio
Analytical Estimate of the Effect of Spherical Inhomogeneities on Luminosity Distance and Redshift
We provide an analytical estimate of the effect of a spherical inhomogeneity
on light beams that travel through it. We model the interior of the
inhomogeneity in terms of the Lemaitre-Tolman-Bondi metric. We assume that the
beam source is located outside the inhomogeneity. We study the relative
deviations of travelling time, redshift, beam area and luminosity distance from
their values in a homogeneous cosmology. They depend on the ratio Hb=H r_0 of
the radius r_0 of the inhomogeneity to the horizon distance 1/H. For an
observer located at the center, the deviations are of order Hb^2. For an
observer outside the inhomogeneity, the deviations of crossing time and
redshift are of order Hb^3. The deviations of beam area and luminosity distance
are of order Hb^2. However, when averaged over all possible locations of the
observer outside the inhomogeneity, they also become of order Hb^3. We discuss
the implications for the possibility of attributing the observed cosmological
acceleration to the emergence of large-scale structure.Comment: 11 pages, references added, discussion expande
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