1,485 research outputs found
Lesson Study and Service Learning in Teacher Preparation
The aim of this paper is to share an teacher preparation experience that combines Lesson Study (LS) with a Service Learning methodology. This experience is interdisciplinary and includes three subjects from first-grade Childhood Education, carried out at University of Malaga since academic year 2014-2015.
Within this framework, our students carry out Service Learning projects for schools in our area that are designed and developed following the LS methodology. Service Learning projects go through the following phases (Puig, J., MartĂn, & Batlle, 2008): 1) Preparation by the teachers involved in the project; 2) Implementation, i.e. developing the project with the students; 3) Evaluation.
The implementation phase also has three sub-phases: preparation, implementation, and round-up. It is here that the LS is developed through the following phases (Soto & PĂ©rez, 2015): 1. Define the problem; 2. Co-operatively design an experimental lesson and its observation process; 3. First experimental lesson; 4. Analyse and review the lesson; 5. Second experimental lesson; 6. Analysis and drafting of conclusions; 7. Presentation in extended context.
We were able to gather evidence on how students teachers resolved different cognitive conflicts during the process. We saw how the LS process, with its phases and cooperative work, allows them to combine creativity and unique talents in a common project that acquires meaning and relevance thanks to Service Learning. This provides a framework that facilitates the construction of solid structures related to the meaning of the educational process, and which can be used to recalibrate what it means to be a Childhood School teacher: a creative, relevant, complex experience that requires recreating the knowledge and experience that students bring with them to the University about what it means to be a Childhood School teacher.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Symbiotic stars in X-rays II: faint sources detected with XMM-Newton and Chandra
We report the detection, with and XMM-, of
faint, soft X-ray emission from four symbiotics stars that were not known to be
X-ray sources. These four object show a -type X-ray spectrum, i.e. their
spectra can be modeled with an absorbed optically thin thermal emission with
temperatures of a few million degrees. Photometric series obtained with the
Optical Monitor on board XMM- from V2416 Sgr and NSV 25735
support the proposed scenario where the X-ray emission is produced in a
shock-heated region inside the symbiotic nebulae.Comment: 5 pages, 1 figure, 2 tables; A&A publishe
Radial velocities and metallicities from infrared Ca II triplet spectroscopy of open clusters II. Berkeley 23, King 1, NGC 559, NGC 6603 and NGC 7245
Context: Open clusters are key to studying the formation and evolution of the
Galactic disc. However, there is a deficiency of radial velocity and chemical
abundance determinations for open clusters in the literature. Aims: We intend
to increase the number of determinations of radial velocities and metallicities
from spectroscopy for open clusters. Methods: We acquired medium-resolution
spectra (R~8000) in the infrared region Ca II triplet lines (~8500 AA) for
several stars in five open clusters with the long-slit IDS spectrograph on the
2.5~m Isaac Newton Telescope (Roque de los Muchachos Observatory, Spain).
Radial velocities were obtained by cross-correlation fitting techniques. The
relationships available in the literature between the strength of infrared Ca
II lines and metallicity were also used to derive the metallicity for each
cluster. Results: We obtain = 48.6+/-3.4, -58.4+/-6.8, 26.0+/-4.3 and
-65.3+/-3.2 km s-1 for Berkeley 23, NGC 559, NGC 6603 and NGC 7245,
respectively. We found [Fe/H] =-0.25+/-0.14 and -0.15+/-0.18 for NGC 559 and
NGC 7245, respectively. Berkeley 23 has a low metallicity, [Fe/H]
=-0.42+/-0.13, similar to other open clusters in the outskirts of the Galactic
disc. In contrast, we derived a high metallicity ([Fe/H] =+0.43+/-0.15) for NGC
6603, which places this system among the most metal rich known open clusters.
To our knowledge, this is the first determination of radial velocities and
metallicities from spectroscopy for these clusters, except NGC 6603, for which
radial velocities had been previously determined. We have also analysed ten
stars in the line of sight to King 1. Because of the large dispersion obtained
in both radial velocity and metallicity, we cannot be sure that we have sampled
true cluster members.Comment: 10 pages, 5 figures, accepted for publication in A&A (minor
modifications
Symbiotic stars in X-rays III: Suzaku observations
We describe the X-ray emission as observed with Suzaku from five symbiotic
stars that we selected for deep Suzaku observations after their initial
detection with ROSAT, ASCA and Swift. We find that the X-ray spectra of all
five sources can be adequately fit with absorbed, optically thin thermal plasma
models, with either single- or multi-temperature plasmas. These models are
compatible with the X-ray emission originating in the boundary layer between an
accretion disk and a white dwarf. The high plasma temperatures of kT keV
for all five targets were greater than expected for colliding winds. Based on
these high temperatures, as well as previous measurements of UV variability and
UV luminosity, and the large amplitude of X-ray flickering in 4 Dra, we
conclude that all five sources are accretion-powered through predominantly
optically thick boundary layers. Our X-ray data allow us to observe a small,
optically thin portion of the emission from these boundary layers. Given the
time between previous observations and these observations, we find that the
intrinsic X-ray flux and the intervening absorbing column can vary by factors
of three or more on a time scale of years. However, the location of the
absorber and the relationship between changes in accretion rate and absorption
are still elusive.Comment: 14 pages, 3 figures and 3 tables. Accepted to published 04/15/2016.
arXiv admin note: substantial text overlap with arXiv:1505.0063
Destined for decline? Examining nuclear energy from a technological innovation systems perspective
Technology decline is a central element of sustainability transitions. However, transition scholars have only just begun to analyze decline. This paper uses the technological innovation systems (TIS) perspective to study decline. Our case is nuclear energy, which is at a crossroads. Some view nuclear as a key technology to address climate change, while others see an industry in decline. We examine a broad range of empirical indicators at the global scale to assess whether or not nuclear energy is in decline. We find that an eroding actor base, shrinking opportunities in liberalized electricity markets, the break-up of existing networks, loss of legitimacy, increasing cost and time overruns, and abandoned projects are clear indications of decline. Also, increasingly fierce competition from natural gas, solar PV, wind, and energy-storage technologies speaks against nuclear in the electricity sector. We conclude that, while there might be a future for nuclear in state-controlled ânichesâ such as Russia or China, new nuclear power plants do not seem likely to become a core element in the struggle against climate change. Our conceptual contribution is twofold. First, we show how the TIS framework can be mobilized to study technology decline. Second, we explore a range of indicators to cover the multiple dimensions of decline, including actors, institutions, technology, and context.info:eu-repo/semantics/acceptedVersio
Determination of transition frequencies in a single Ba ion
Transition frequencies between low-lying energy levels in a single trapped
Ba ion have been measured with laser spectroscopy referenced to
an optical frequency comb. By extracting the frequencies of one-photon and
two-photon components of the line shape using an eight-level optical Bloch
model, we achieved 0.1 MHz accuracy for the 5d D - 6p
P and 6s S - 5d D transition
frequencies, and 0.2 MHz for the 6s S - 6p P
transition frequency.Comment: 5 pages, 7 figures, submitted to Phys. Rev.
Improved serodiagnosis of alveolar echinococcosis of humans using an in vitro-produced Echinococcus multilocularis antigen
Serology is an important tool for the diagnosis of alveolar echinococcosis (AE) in humans. In order to improve serodiagnostic performance, we have developed an in vitro-produced Echinococcus mulilocularis metacestode vesicle fluid (EmVF) antigen for application in an immunoblot assay. Immunoblot analysis of EmVF revealed an abundant immunoreactive band triplet of 20-22kDa, achieving a sensitivity of 100% based on the testing of sera from 62 pre-operative and pre-treatment cases of active and inactive AE. Thus, the EmVF-immunoblotting allowed the specific detection of cases seronegative by the Em2- and/or EmII/3-10-ELISA, usually attributable to abortive, inactive cases of AE. The specificity of the EmVF-immunoblotting did not allow discrimination between AE and cystic echinococcosis (CE) but was 100% with respect to non-Echinococcus parasitic infections or cancer malignancies. Based on the findings of this study, it is recommended that the current ELISA test combination (Em2- and II/3-10-ELISA) be complemented with EmVF-immunoblotting, allowing an improved diagnosis of both clinical and subclinical forms of AE, including those associated with E. multilocularis-specific antibody reactivities not detectable by ELIS
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