4,235 research outputs found
The Effect of Teacher Candidatesâ Perceptions of Their Initial Teacher Education Program on Teaching Anxiety, Efficacy, and Commitment
In a novel approach to initial teacher education, we combined a program review perspective and a psychological perspective. First, we assessed the extent to which student teachers (n=137) felt that components of their BEd program prepared them for teaching and whether these components represented meaningful program dimensions. Through content analysis, exploratory factor analysis, and teacher candidatesâ own words, five dimensions emerged: classroom dynamics; curriculum, instruction, and assessment; intrapersonal reflection; ethics of teaching; and professional learning community. Second, we tested how each of these dimensions predicted teaching anxiety, efficacy, and commitment. The results from regression analyses showed that ethics of teaching was the most influential dimension by decreasing anxiety and increasing efficacy and commitment. Results are discussed in terms of the effect of initial teacher education program dimensions on the psychosocial development of teacher candidates.Adoptant une approche novatrice Ă la formation initiale des enseignants, nous avons combinĂ© une perspective visant l'examen des programmes avec une perspective psychologique. Nous avons d'abord Ă©valuĂ© la mesure dans laquelle les stagiaires (n=137) estimaient que des composantes de leur programme d'Ă©tudes (B.Ed.) les avaient prĂ©parĂ©s pour l'enseignement et Ă quel point ces composantes reprĂ©sentaient des dimensions significatives de leurs programmes. Cinq dimensions ont dĂ©coulĂ© des analyses du contenu, des facteurs exploratoires et des propres paroles des stagiaires : la dynamique en salle de classe; le programme dâĂ©tude, lâenseignement et lâĂ©valuation; la rĂ©flexion intrapersonnelle; lâĂ©thique et lâenseignement; et les communautĂ©s professionnelles dâenseignement. Nous avons ensuite Ă©valuĂ© dans quelle mesure chacune de ces dimensions constituait une variable explicative de lâanxiĂ©tĂ©, lâefficacitĂ© et lâengagement en enseignement. Les rĂ©sultats sont prĂ©sentĂ©s en fonction de lâeffet des dimensions du programme de formation initiale des enseignants sur le dĂ©veloppement psychosocial des stagiaires
Graph Neural Networks and Applied Linear Algebra
Sparse matrix computations are ubiquitous in scientific computing. With the
recent interest in scientific machine learning, it is natural to ask how sparse
matrix computations can leverage neural networks (NN). Unfortunately,
multi-layer perceptron (MLP) neural networks are typically not natural for
either graph or sparse matrix computations. The issue lies with the fact that
MLPs require fixed-sized inputs while scientific applications generally
generate sparse matrices with arbitrary dimensions and a wide range of nonzero
patterns (or matrix graph vertex interconnections). While convolutional NNs
could possibly address matrix graphs where all vertices have the same number of
nearest neighbors, a more general approach is needed for arbitrary sparse
matrices, e.g. arising from discretized partial differential equations on
unstructured meshes. Graph neural networks (GNNs) are one approach suitable to
sparse matrices. GNNs define aggregation functions (e.g., summations) that
operate on variable size input data to produce data of a fixed output size so
that MLPs can be applied. The goal of this paper is to provide an introduction
to GNNs for a numerical linear algebra audience. Concrete examples are provided
to illustrate how many common linear algebra tasks can be accomplished using
GNNs. We focus on iterative methods that employ computational kernels such as
matrix-vector products, interpolation, relaxation methods, and
strength-of-connection measures. Our GNN examples include cases where
parameters are determined a-priori as well as cases where parameters must be
learned. The intent with this article is to help computational scientists
understand how GNNs can be used to adapt machine learning concepts to
computational tasks associated with sparse matrices. It is hoped that this
understanding will stimulate data-driven extensions of classical sparse linear
algebra tasks
User experience analysis of AbC-19 Rapid Test via lateral flow immunoassays for self-administrated SARS-CoV-2 antibody testing
Abstract Lateral flow immunoassays are low cost, rapid and highly efficacious point-of-care devices, which have been used for SARS-CoV-2 antibody testing by professionals. However, there is a lack of understanding about how self-administered tests are used by the general public for mass testing in different environmental settings. The purpose of this study was to assess the user experience (UX) (including usability) of a self-testing kit to identify COVID-19 antibodies used by a representative sample of the public in their cars, which included 1544 participants in Northern Ireland. The results based on 5-point Likert ratings from a post-test questionnaire achieved an average UX score of 96.03% [95% confidence interval (CI) 95.05â97.01%], suggesting a good degree of user experience. The results of the Wilcoxon rank sum tests suggest that UX scores were independent of the userâs age and education level although the confidence in this conclusion could be strengthened by including more participants aged younger than 18 and those with only primary or secondary education. The agreement between the test result as interpreted by the participant and the researcher was 95.85% [95% CI 94.85â96.85%], Kappa score 0.75 [95% CI 0.69â0.81] (indicating substantial agreement). Text analysis via the latent Dirichlet allocation model for the free text responses in the survey suggest that the user experience could be improved for blood-sample collection, by modifying the method of sample transfer to the test device and giving clearer instructions on how to interpret the test results. The overall findings provide an insight into the opportunities for improving the design of SARS-CoV-2 antibody testing kits to be used by the general public and therefore inform protocols for future user experience studies of point-of-care tests
ENERGETIC COSTS AND STRATEGIES OF POSTâJUVENAL MOLT IN AN EQUATORIAL BIRD, THE RUFOUSâCOLLARED SPARROW (ZONOTRICHIA CAPENSIS)
Abstract â Many tropical birds have slowâpaced life history strategies, exhibiting lower metabolic rates, reduced annual investment in reproduction, and longer lifespans relative to birds at higher latitudes. Life history strategies have been relatively well documented in adult individuals in the tropics, but we know comparatively little about the immature life history stage. Here we examine strategies of feather replacement (molt) and fattening in immature Rufousâcollared Sparrows (Zonotrichia capensis) in a high elevation equatorial population, following a parallel, previous study on an arctic congener, the Whiteâcrowned Sparrow (Zonotrichia leucophrys gambelii). In captivity, Rufousâ collared Sparrows incurred energetic costs of experimentally induced feather growth, similar to those previously described for Zonotrichia at higher latitudes. In contrast, freeâranging immature Rufousâcollared Sparrows in natural molt had fat stores that declined over time, opposite to patterns evident in arctic Zonotrichia that fatten before migration. Equatorial birds in good condition molted more heavily (controlling for fat stores), suggesting that body condition limits the intensity of molt. Heavily molting equatorial sparrows also had lower amounts of fat (controlling for body condition), suggesting a tradeâoff between allocation of resources to fat stores versus feather growth. Molt progressed slowly in Rufousâcollared Sparrows relative to previously described patterns in their arctic congener, which is concordant with a slower paceâofâlife syndrome in tropical, as compared with high latitude, birds. Resumen â Costos energĂ©ticos y estrategias de muda postâjuvenil en un ave ecuatorial, el Chingolo (Zonotrichia capensis) Muchas especies de aves tropicales presentan historias de vida lenta, exhibiendo bajas tasas metabĂłlicas, esfuerzo reproductivo anual reducido, y mayor longevidad que las especies que habitan en latitudes mĂĄs altas. La variaciĂłn en historia de vida en especies tropicales ha sido bien documentada para individuos adultos, pero sabemos comparativaâ mente poco de los individuos inmaduros. AquĂ estudiamos las estrategias de muda y deposiciĂłn de grasa en individuos inmaduros de Chingolo (Zonotrichia capensis) en una poblaciĂłn ecuatorial de altura y comparamos los resultados con un estudio similar realizado en una poblaciĂłn ĂĄrtica del congĂ©nere Chingolo Coroniblanco (Zonotrichia leucophrys gambelii). En cautiverio, individuos juveniles de Z. capensis incurrieron costos energĂ©ticos debidos a la muda inducida, similar lo encontrado en Z. leucophrys gambelii. En contraste, Z. capensis inmaduros mudando en libertad presentaron depĂłsitos de grasa que disminuyeron a lo largo del tiempo, lo opuesto a Z. l. gambelii, que deposita mĂĄs grasa antes de migrar. Z. capensis inmaduros en buen estado nutricional (controlando por diferencias en deposiciĂłn de grasa) mudaron de manera mĂĄs intensa, lo que sugiere que el estado nutricional limita la muda. Individuos inmaduros de Z. capensis mudando de manera intensa presentaron menor cantidad de grasa depositada (controlando por diferencias en estado nutricional), lo que sugiere un balance entre la deposiciĂłn de grasa y la muda. La muda fue mĂĄs lenta en la poblaciĂłn ecuatorial de Z. capensis comparado con la de Z. l. gambelii, lo que concuerda con lo esperado debido a la historia de vida mĂĄs lenta en aves tropicales
Unconventional ferromagnetic and spin-glass states of the reentrant spin glass Fe0.7Al0.3
Spin excitations of single crystal Fe0.7Al0.3 were investigated over a wide
range in energy and reciprocal space with inelastic neutron scattering. In the
ferromagnetic phase, propagating spin wave modes become paramagnon-like
diffusive modes beyond a critical wave vector q0, indicating substantial
disorder in the long-range ordered state. In the spin glass phase, spin
dynamics is strongly q-dependent, suggesting remnant short-range spin
correlations. Quantitative model for S(energy,q) in the ``ferromagnetic'' phase
is determined.Comment: 4 pages, 5 figure
Detailed Retinal Imaging In Carriers Of Ocular Albinism
BACKGROUND:
Albinism refers to a group of disorders primarily characterized by hypopigmentation. Affected individuals usually manifest both ocular and cutaneous features of the disease, but occasionally hair and skin pigmentation may appear normal. This is the case in ocular albinism, an X chromosome linked disorder resulting from mutation of GPR143. Female carriers may be recognized by a "mud-splatter" appearance in the peripheral retina. The macula is thought to be normal, however.
METHODS:
Obligate female carriers of pathogenic GPR143 alleles were recruited. Molecular confirmation of disease was performed only for atypical cases. Detailed retinal imaging was performed (colour fundus photography, optical coherence tomography, fundus autofluorescence.
RESULTS:
Eight individuals were ascertained. A novel GPR143 mutation was identified in one family (p.Gln328Ter). Foveal fundus autofluorescence was subjectively reduced in 6/6 patients imaged. A "tapetal-like" pattern of autofluorescence was visible at the macula in 3/6. Persistence of the inner retinal layers at the fovea was observed in 6/8 females.
CONCLUSION:
Female carriers of ocular albinism may manifest signs of retinal pigment epithelium mosaicism at the macula and the peripheral fundus. A tapetal-like reflex on fundus autofluorescence may be considered the macular correlate of "mud-splatter.
Attracting Manifold for a Viscous Topology Transition
An analytical method is developed describing the approach to a finite-time
singularity associated with collapse of a narrow fluid layer in an unstable
Hele-Shaw flow. Under the separation of time scales near a bifurcation point, a
long-wavelength mode entrains higher-frequency modes, as described by a version
of Hill's equation. In the slaved dynamics, the initial-value problem is solved
explicitly, yielding the time and analytical structure of a singularity which
is associated with the motion of zeroes in the complex plane. This suggests a
general mechanism of singularity formation in this system.Comment: 4 pages, RevTeX, 3 ps figs included with text in uuencoded file,
accepted in Phys. Rev. Let
CWRML: representing crop wild relative conservation and use data in XML
Background
Crop wild relatives are wild species that are closely related to crops. They are valuable as potential gene donors for crop improvement and may help to ensure food security for the future. However, they are becoming increasingly threatened in the wild and are inadequately conserved, both in situ and ex situ. Information about the conservation status and utilisation potential of crop wild relatives is diverse and dispersed, and no single agreed standard exists for representing such information; yet, this information is vital to ensure these species are effectively conserved and utilised. The European Community-funded project, European Crop Wild Relative Diversity Assessment and Conservation Forum, determined the minimum information requirements for the conservation and utilisation of crop wild relatives and created the Crop Wild Relative Information System, incorporating an eXtensible Markup Language (XML) schema to aid data sharing and exchange.
Results
Crop Wild Relative Markup Language (CWRML) was developed to represent the data necessary for crop wild relative conservation and ensure that they can be effectively utilised for crop improvement. The schema partitions data into taxon-, site-, and population-specific elements, to allow for integration with other more general conservation biology schemata which may emerge as accepted standards in the future. These elements are composed of sub-elements, which are structured in order to facilitate the use of the schema in a variety of crop wild relative conservation and use contexts. Pre-existing standards for data representation in conservation biology were reviewed and incorporated into the schema as restrictions on element data contents, where appropriate.
Conclusion
CWRML provides a flexible data communication format for representing in situ and ex situ conservation status of individual taxa as well as their utilisation potential. The development of the schema highlights a number of instances where additional standards-development may be valuable, particularly with regard to the representation of population-specific data and utilisation potential. As crop wild relatives are intrinsically no different to other wild plant species there is potential for the inclusion of CWRML data elements in the emerging standards for representation of biodiversity data
Mapping the Operation of the Miniature Combustion Aerosol Standard (Mini-CAST) Soot Generator
The Jing Ltd. miniature combustion aerosol standard (Mini- CAST) soot generator is a portable, commercially available burner that is widely used for laboratory measurements of soot processes. While many studies have used the Mini-CAST to generate soot with known size, concentration, and organic carbon fraction under a single or few conditions, there has been no systematic study of the burner operation over a wide range of operating conditions. Here, we present a comprehensive characterization of the microphysical, chemical, morphological, and hygroscopic properties of Mini- CAST soot over the full range of oxidation air and mixing N2 flow rates. Very fuel-rich and fuel-lean flame conditions are found to produce organic-dominated soot with mode diameters of 10â60 nm, and the highest particle number concentrations are produced under fuel-rich conditions. The lowest organic fraction and largest diameter soot (70â130 nm) occur under slightly fuel-lean conditions. Moving from fuel-rich to fuel-lean conditions also increases the O:C ratio of the soot coatings from ~0.05 to ~0.25, which causes a small fraction of the particles to act as cloud condensation nuclei near the Kelvin limit (Îș ~ 0â10â3). Comparison of these property ranges to those reported in the literature for aircraft and diesel engine soots indicates that the Mini-CAST soot is similar to real-world primary soot particles, which lends itself to a variety of process-based soot studies. The trends in soot properties uncovered here will guide selection of burner operating conditions to achieve optimum soot properties that are most relevant to such studies
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