School Resources and the Academic Achievement of Canadian Students

This study estimates the impact of schools’ physical resources and teachers’ academic press on students’ academic achievement in mathematics and reading when a number of important student variables are controlled. Academic press is defined as teachers' emphasis on academic excellence and upholding academic standards (McDill, Natriello, & Pallas, 1986). It is often argued that both school and teacher resources affect the educational achievement of students. But, the research literature has been inconsistent, which may be due to methodological issues. For this reason, this study attempts to correct two of the most important issues by using Canadian national data and multi-level modeling. The results reveal that, in Canada, at least, the physical resources and academic press evaluated by school principals do not significantly affect students’ achievement in mathematics and reading. Cette étude évalue l’impact des ressources physiques des écoles et la rigueur académique des enseignants sur le rendement académique des élèves en mathématiques et en lecture lorsqu’on contrôle un certain nombre de variables importants chez les élèves. On définit la rigueur académique comme l’importance que les enseignants accordent à l’excellence académique et le maintien de normes académiques (McDill, Natriello, & Pallas, 1986). On soutient souvent que tant les ressources de l’école que celles des enseignants jouent un rôle dans le rendement académique des élèves. Les publications de recherche, par contre, sont contradictoires, peut-être en raison de problèmes méthodologiques. Cette étude tente donc de rectifier deux des problèmes les plus importants en employant des données nationales canadiennes et le modelage multiniveau. Les résultats indiquent qu’au Canada du moins, les ressources physiques et la rigueur académique telles qu’évaluées par les directeurs d’école n’affectent pas de façon significative le rendement des élèves en mathématiques et en lecture

Mathematic Achievement of Canadian Private School Students

Very little Canadian research has examined the academic achievement of private school students. Data from The Programme for International Student Assessment (PISA) 2003 were used to examine the achievement of private school students. The study found that private school students outperformed their public school peers. In addition, the students’ morale, motivation, interest in mathematics, expected education, effort invested in the PISA test, and socioeconomic status were significantly and positively related to their academic performance. Surprisingly, the cost of their tuition fees, reported hours spent on math homework, sense of belonging, and higher ratio of instructional time on mathematics were significantly, but negatively, related to the students’ math performance.Au Canada, le rendement académique d’élèves dans les écoles privées a très peu fait l’objet de recherche. Nous avons étudié les données du Programme international pour le suivi des acquis des élèves (PISA) de 2003 pour évaluer le rendement des élèves dans les écoles privées; notre étude est similaire à une étude récente portant sur le rendement académique d’élèves dans les écoles publiques au Canada (Wei, Clifton, & Roberts, 2011). Nos résultats indiquent que le rendement des élèves dans les écoles privées est supérieur à celui des élèves dans les écoles publiques. De plus, nous avons trouvé plusieurs facteurs ayant un effet significatif et positif sur le rendement académique :  le moral, la motivation, l’intérêt pour les mathématiques, les attentes quant à leur scolarisation, les efforts consentis pour bien réussir au PISA et le statut socioéconomique. Étonnamment, les facteurs suivants exerçaient un effet significatif, mais négatif, sur la performance des élèves en mathématiques : le cout des frais de scolarité, les heures qu’ils disaient passer à faire des devoirs en mathématiques, le sentiment d’appartenance et un rapport plus élevé d’heures d’enseignement des mathématiques

Retinal oscillations carry visual information to cortex

Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs) and thalamic outputs (spikes) and analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz), is encoded by average firing rate with respect to the stimulus and carries information about local changes in the image over time. The other operates in the gamma frequency band (40-80 Hz) and is encoded by spike time relative to the retinal oscillations. Because these oscillations involve extensive areas of the retina, it is likely that the second channel transmits information about global features of the visual scene. At times, the second channel conveyed even more information than the first.Comment: 21 pages, 10 figures, submitted to Frontiers in Systems Neuroscienc

Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood, which causes controversial conclusions about their genesis. Here we show that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in environment and serve a special role in Earth’s history, such as Fe3+ and Al3+. GQDs self- assemble into mesoscale chains, sheets, supraparticles, nanoshells, and nanostars. Specific assembly patterns are determined by the effective symmetry of the GQDs when forming the coordination assemblies with the metal ions. As such, maximization of the electronic delocalization of Ï - orbitals of GQDs with Fe3+ leads to GQD- Fe- GQD units with D2 symmetry, dipolar bonding potential, and linear assemblies. Taking advantage of high electron microscopy contrast of carbonaceous nanostructures in respect to ceramic background, the mineralogical counterparts of GQD assemblies are found in mineraloid shungite. These findings provide insight into nanoparticle dynamics during the rock formation that can lead to mineralized structures of unexpectedly high complexity.Komplexe Strukturen aus Nanopartikeln sind in Gesteinen, Böden und Meeressedimenten zu finden, aber die Mechanismen ihrer Entstehung sind kaum verstanden. Es wird gezeigt, dass sich Graphenquantenpunkte (GQDs) zu komplexen Strukturen zusammenfügen können, angetrieben durch Koordinationswechselwirkungen mit Metallionen wie Fe3+ and Al3+, die in der Umwelt häufig vorkommen und eine besondere Rolle in der Erdgeschichte spielen.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/1/ange201908216.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/2/ange201908216_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155470/3/ange201908216-sup-0001-misc_information.pd

Diverse Nanoassemblies of Graphene Quantum Dots and Their Mineralogical Counterparts

Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood, which causes controversial conclusions about their genesis. Here we show that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in environment and serve a special role in Earth’s history, such as Fe3+ and Al3+. GQDs self- assemble into mesoscale chains, sheets, supraparticles, nanoshells, and nanostars. Specific assembly patterns are determined by the effective symmetry of the GQDs when forming the coordination assemblies with the metal ions. As such, maximization of the electronic delocalization of Ï - orbitals of GQDs with Fe3+ leads to GQD- Fe- GQD units with D2 symmetry, dipolar bonding potential, and linear assemblies. Taking advantage of high electron microscopy contrast of carbonaceous nanostructures in respect to ceramic background, the mineralogical counterparts of GQD assemblies are found in mineraloid shungite. These findings provide insight into nanoparticle dynamics during the rock formation that can lead to mineralized structures of unexpectedly high complexity.Complex structures from nanoparticles are found in rocks, soils, and sea sediments but the mechanisms of their formation are poorly understood. It is shown that graphene quantum dots (GQDs) can assemble into complex structures driven by coordination interactions with metal ions commonly present in the environment and play a special role in Earth’s history, such as Fe3+ and Al3+.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/1/anie201908216_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/2/anie201908216.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155475/3/anie201908216-sup-0001-misc_information.pd

Online Preconcentration and Determination of Trace Amounts of Zinc in Nature Waters

A simple, sensitive, reliable and flexible flow injection spectrophotometric method is proposed for on-line preconcentration and determination of trace amounts of zinc in water. At the presence of Tween-80 in pH 9.3 buffer solutions, the shade of color of Zn (II)-PAN complex is in a linear relation to the zinc amount at the point of the maximum absorption peak of 560 nm. The optimal experimental conditions, including reaction conditions and preconcentration conditions, had been obtained. The linear range of the proposed method was between 2.0 and 360 μg L−1 and the detection limit was 0.42 μg L−1. The relative standard deviation was 3.55% and 2.14% for 5.0 μg L−1 and 50 μg L−1 of zinc standard solution (n = 8). The method had been successfully applied to zinc determination in water samples and the analytical results were satisfactory

Effects of transition elements on the site preference, elastic properties and phase stability of L1 2 γ′-Co 3 (Al, W) from first-principles calculations

Abstract(#br)We performed a systematic study of alloying effects on the site preference, elastic properties and phase stability of L1 2 γ′-Co 3 (Al, W) in terms of the first-principles calculations. Up to twenty-one transition metal elements (Sc, Ti, V, Cr, Mn, Fe, Ni, Y, Zr, Nb, Mo, Tc, Ru. Rh, Pd, Hf, Ta, Re, Os, Ir and Pt) were considered in this work. We find that Sc, Ti, V, Cr, Mn, Y, Zr, Nb, Mo, Tc, Hf, Ta, Re and Os favor to occupy the Al site, and Fe, Ni, Ru. Rh, Pd, Ir and Pt favor to occupy the Co site, except for Y, Fe and Ru, other transition metal elements can stabilize the L1 2 γ′-Co 3 (Al, W) at 0 K. By using stress-strain method, the elastic properties including bulk modulus, shear modulus and Young’s modulus were evaluated. It is verified that the elastic properties of L1 2 γ′-Co 3 (Al, W) depend on not only volume change but also electron density as well as electronic configurations. The thermodynamic results of phase stability of L1 2 γ′-Co 3 (Al, W) reveal that Hf, Ti and Ta are the promising alloying elements to improve the stability of L1 2 γ′-Co 3 (Al, W)

FIMO: A Challenge Formal Dataset for Automated Theorem Proving

We present FIMO, an innovative dataset comprising formal mathematical problem statements sourced from the International Mathematical Olympiad (IMO) Shortlisted Problems. Designed to facilitate advanced automated theorem proving at the IMO level, FIMO is currently tailored for the Lean formal language. It comprises 149 formal problem statements, accompanied by both informal problem descriptions and their corresponding LaTeX-based informal proofs. Through initial experiments involving GPT-4, our findings underscore the existing limitations in current methodologies, indicating a substantial journey ahead before achieving satisfactory IMO-level automated theorem proving outcomes