83 research outputs found
Becoming a teacher: conceptual and practice development in the learning and skills sector
Drawing on a mixed-methods study of in-service learning and skills sector (LSS) trainees, comprising beginning- and end-of-year surveys and six longitudinal case studies together with literature on traineesâ development in the LSS, schools and higher education sectors, conceptual and practice development continua are proposed. Conceptions become more multi-dimensional and increasingly link teaching and learning whilst initial concern with the practicalities of teaching is followed by recognition of learnersâ needs. Next, greater emphasis is placed on learner autonomy and catering for individualsâ needs and finally assessment and evaluation is used systematically to shape practice. The continua offer an understanding of the subtleties and complexities of trainee development allowing
for different starting and end points and accommodating varied work contexts. I argue that this provides a more adequate basis for the development of initial teacher education (ITE) than the prescriptive approach embedded within recent LSS ITE policy reforms
Reuse as heuristic : from transmission to nurture in learning activity design
In recent years a combination of ever more flexible and sophisticated Web technologies and an explosion in the quantity of online content has sparked learning technologists around the world to pursue the promise of the 'reusable learning object' or RLO with the idea that RLOs could be reused in different educational contexts, thereby providing greater overall flexibility and return on investment. In 2002 the ACETS Project undertook a three-year study in the UK to investigate whether RLOs worked in practice and how the pursuit of reuse affected the teacher and their teaching. Teachers working in healthcare-related subjects in Higher and Further Education were asked to create an original learning design or activity from third-party digital resources and to reflect both on the process and its outcomes. The expectation was that teachers would be the ones selecting and reusing third-party materials. This paper describes how one of the ACETS exemplifiers reinterpreted this remit, challenged the anticipated transmissive model of learning, and instead, gave their students an opportunity to create their own original learning designs and learning activities from third-party digital resources. By describing the educational enhancements, the resulting heightened levels of critical thinking, and sensitivity to patient needs, 'reuse' will be shown to be an effective heuristic for student self-direction and professional development
Trapped Particle Stability for the Kinetic Stabilizer
A kinetically stabilized axially symmetric tandem mirror (KSTM) uses the
momentum flux of low-energy, unconfined particles that sample only the outer
end-regions of the mirror plugs, where large favorable field-line curvature
exists. The window of operation is determined for achieving MHD stability with
tolerable energy drain from the kinetic stabilizer. Then MHD stable systems are
analyzed for stability of the trapped particle mode. This mode is characterized
by the detachment of the central-cell plasma from the kinetic stabilizer region
without inducing field-line bending. Stability of the trapped particle mode is
sensitive to the electron connection between the stabilizer and the end plug.
It is found that the stability condition for the trapped particle mode is more
constraining than the stability condition for the MHD mode, and it is
challenging to satisfy the required power constraint. Furthermore a severe
power drain may arise from the necessary connection of low-energy electrons in
the kinetic stabilizer to the central region
Longitudinal scaling property of the charge balance function in Au + Au collisions at 200 GeV
We present measurements of the charge balance function, from the charged
particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au
collisions at 200 GeV using the STAR detector at RHIC. We observe that the
balance function is boost-invariant within the pseudorapidity coverage [-1.3,
1.3]. The balance function properly scaled by the width of the observed
pseudorapidity window does not depend on the position or size of the
pseudorapidity window. This scaling property also holds for particles in
different transverse momentum ranges. In addition, we find that the width of
the balance function decreases monotonically with increasing transverse
momentum for all centrality classes.Comment: 6 pages, 3 figure
Enhanced phosphorus removal in a waste stabilization pond system with blast furnace slag filters
Particles-vortex interactions and flow visualization in He4
Recent experiments have demonstrated a remarkable progress in implementing
and use of the Particle Image Velocimetry (PIV) and particle tracking
techniques for the study of turbulence in He4. However, an interpretation of
the experimental data in the superfluid phase requires understanding how the
motion of tracer particles is affected by the two components, the viscous
normal fluid and the inviscid superfluid. Of a particular importance is the
problem of particle interactions with quantized vortex lines which may not only
strongly affect the particle motion, but, under certain conditions, may even
trap particles on quantized vortex cores. The article reviews recent
theoretical, numerical, and experimental results in this rapidly developing
area of research, putting critically together recent results, and solving
apparent inconsistencies. Also discussed is a closely related technique of
detection of quantized vortices negative ion bubbles in He4.Comment: To appear in the J Low Temperature Physic
Ação do cepa e do åcido giberélico na frutificação da videira 'niagara rosada'
Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the JundiaĂ Research Station, Agronomic Institute State of SĂŁo Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersĂŁo, do CEPA (ĂĄcido 2-cloroetil fosfĂŽnico) e do ĂĄcido giberĂ©lico, 14 dias antes do florescimento, nas caracterĂsticas morfolĂłgicas da panĂcula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ĂĄcido giberĂ©lico foram concluĂdos com nova aplicação 10 dias apĂłs o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panĂculas com a maioria de caracterĂsticas indesejĂĄveis. o tratamento misto CEPA 100 ppm + ĂĄcido giberĂ©lico 100 ppm tambĂ©m promoveu o aparecimento de panĂculas subdesenvolvidas. Aplicação de ĂĄcido giberĂ©lico na concentração de 100 ppm em prĂ© e pĂłs-Ălorescimento, resultou mĂ©dias mais elevadas, com relação ao peso da panĂcula, comprimento da panĂcula, peso das bagas e comprimento da rĂĄquis. Ăcido giberĂ©lico na concentração de 100 ppm aplicado em pĂłs-Ălorescimento, promoveu uma tendĂȘncia de aumento nas mĂ©dias do tratamento quanto ao comprimento mĂ©dio das bagas, largura mĂ©dia das bagas, largura do engaço e comprimento da rĂĄquila. Devemos considerar porĂ©m, que os resultados obtidos nĂŁo apresentaram diferenças significativas com relação ao controle, quanto Ă s caracterĂsticas das frutificaçÔes, nas condiçÔes de estudo
Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58Ă10-8, Ω0V<6.35Ă10-8, and Ω0S<1.08Ă10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society
Genome-wide association meta-analysis identifies five novel loci for age-related hearing impairment
Previous research has shown that genes play a substantial role in determining a person's susceptibility to age-related hearing impairment. The existing studies on this subject have different results, which may be caused by difficulties in determining the phenotype or the limited number of participants involved. Here, we have gathered the largest sample to date (discovery nâ=â9,675; replication nâ=â10,963; validation nâ=â356,141), and examined phenotypes that represented low/mid and high frequency hearing loss on the pure tone audiogram. We identified 7 loci that were either replicated and/or validated, of which 5 loci are novel in hearing. Especially the ILDR1 gene is a high profile candidate, as it contains our top SNP, is a known hearing loss gene, has been linked to age-related hearing impairment before, and in addition is preferentially expressed within hair cells of the inner ear. By verifying all previously published SNPs, we can present a paper that combines all new and existing findings to date, giving a complete overview of the genetic architecture of age-related hearing impairment. This is of importance as age-related hearing impairment is highly prevalent in our ageing society and represents a large socio-economic burden
On the progenitor of binary neutron star merger GW170817
On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just âŒ40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of âŒ2 kpc away from the galaxy's center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy's star formation history, provided the stellar populations are older than 1 Gyr
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