Into the Fray: Novice Teachers Tackle Standards-Based Mathematics

This article tracks twenty-one graduates of a refom-based mathematics teacher education program for two years as they begin teaching mathematics in public elementary schools in New York City. Using surveys, classroom observations, and interviews, it examines the extent to which these beginning teachers were able to implement standards-based mathematics instruction in their classes. Results of the study were mixed. The novice teachers generally demonstrated an adequate understanding of the underlying mathematics principles and strong intentions of teaching mathematics for understanding.They were generally able to engage children in learning, and most performed at the “beginning stages of effective instruction” in their first year. However, they still struggled to engage students in higher order thinking and knowledge construction. ln their second year their abilities improved, but they were still hampered by local factors such as insufficient in-service support, the restrictions of high-stakes testing, and the overall school climate

Trend du Sex-ratio par la théorie de jeux évolutifs

Dans cet article, nous étudions l’influence génétique et sexuelle aussi bien mâle que femelle sur le génome mâle. La parité de ces allocations génétiques et sexuelles suit un cheminement d’un équilibre évolutivement stable qui induit implicitement une proportion, sex-ratio, génétiquement paritaire. La disparitéobservée en faveur d’un tel taux supérieur à l’unitépeut ainsi s’expliquer par la discrimination sexuelle et féminine

Developing Effective Mathematics Teaching: Assessing Content and Pedagogical Knowledge, Student-Centered Teaching, and Student Engagement

The Mathematics Teacher Transformation Institutes (MTTI) program attempts to develop math teacher leaders in part by providing content, inquiry and leadership courses aimed at making them more effective teachers. We assessed progress by observing teacher leaders’ teaching practices, and encouraging them to introduce or extend studentcentered pedagogy in their classrooms. We found there was little relationship between our measures of mathematics content knowledge and student‐centered pedagogy. But teachers who employed student‐centered pedagogy tended to have more highly‐engaged math students in their classrooms

OPTIMIZATION AND ANALYSIS OF THE INDEX OF AIR QUALITY IN DAKAR BY THE PROCESS AUTO REGRESSIVE MOVING AVERAGE ARMA(2,1)

Abstract: Numerous time-dependent phenomena govern our world. The time series are part of one of the methods often used to understand mathematically. Time series can be used to predict future events. In this article, we use the concept of time series to analyze and model the Index of air quality in Dakar to make his short-term forecast. To top this approach, the auto-regressive moving average(2,1) selected by the optimal Akaike information criterion and Bayesian information criterion was used to perform some simulations

Nucleophilic displacement versus electron transfer in the reactions of alkyl chlorosilanes with electrogenerated aromatic anion radicals

International audienceAnion radicals of a series of aromatic compounds (C6H5CN, C6H5COOEt, anthracene, 9,10-dimethyl-, 9,10-diphenyl- and 9-phenylanthracene, pyrene and naphthalene) react with trialkyl chlorosilanes R1R2R3SiCl (R1-3 = Me, Et; R1,2 = Me, R3 = t-Bu) in multiple ways, following classical bimolecular schemes. The ratio of one-electron transfer (ET) to a two-electron process (SN2-like nucleophilic attack of the reduced form of mediator on the chlorosilane, with k2 ≅ 102-108 M−1 s−1) is inversely related to the steric availability of Si for nucleophilic displacement reactions. The nucleophilic substitution pathway mainly results in mono- and disilylated aromatic products. Paralleling the electrochemical data with DFT calculations, the role of silicophilic solvent (DMF) in SN process was shown to be quite complex because of its involvement into coordination extension at silicon, dynamically modifying energetics of the process along the reaction coordinate. Although 2,2'-bipyridine also forms delocalized persistent anion radicals, they do not induce neither ET nor SN reactions in the same manner as aromatic mediators. Silicophilicity of 2,2'-bipyridine being superior to that of DMF, a R3SiCl·bipy complex of hypercoordinated silicon with electroactive ligand was formed instead, whose reduction requires about 1 V less negative potentials than bipyridine itself

COPPER(II) COMPLEXES OF o-VANILLIN ACETYLHYDRAZONE (H2L) AND THE SINGLE-CRYSTAL X-RAY STRUCTURE OF [{Cu(HL)(H

A hydrazonic ligand, o-vanillin acetylhydrazone (H2L) has been prepared and used as chelating agent towards copper(II) ion. The ligand acts like a tridentate ligand in the monodeprotonated (HL-) and dideprotonated (L2-) states. Monoanionic complexes [{Cu(HL)(H2O)}2]•2BF4 and [{Cu(HL)(Hpz)(H2O)}]•NO3 have been isolated. After neutralization the complex [{Cu(L)}2].5/2H2O is obtained. These complexes have been characterized by a range of physicochemical and spectroscopic studies. The X-ray crystal structure of the mononuclear complex [{Cu(HL)(Hpz)(H2O)}]•NO3 was also determined. This crystal is orthorombic with the space group I222, a = 13.417(3), b = 22.662(6), c = 22.518(5) Å, α = β = γ = 90° and Z = 8. The copper ion has a square-pyramidal geometry with the basal donors atoms from the tridentate ligand (ONO) and the pyrazole (N), the apical position being occupied by a coordinated water molecule weakly linked to the copper(II) center. The binuclear complexes exhibit interesting magnetic properties. KEY WORDS: Copper(II) complexes, Tridentate ligand, o-Vanillin acetylhydrazone, X-Ray crystal structure Bull. Chem. Soc. Ethiop. 2006, 20(1), 35-43

The Relationship between Teacher Leadership and School Climate: Findings from a Teacher-Leadership Project

A positive school climate and teacher leadership have both been shown to have beneficial effects on student achievement. This study was part of a wider research effort designed to assess the effects of a teacher-leadership development project. We hypothesized that there was a positive relationship between teacher leadership development and school climate. Seventy project participants from two cohorts responded to a teacher-leadership survey and 891 personnel from 42 schools from which participant teachers were drawn responded to a school climate survey. We found that, generally, there was little relationship between school climate and teacher-leadership development. However, a more fine-grained analysis showed that, for Cohort 2, schools that encourage teacher-to-teacher interactions are likely to see personal growth and development in teacher leaders in their staff. Additional findings suggest that if teacher-to-teacher interactions are encouraged, then teachers will increase their development as teacher leaders. However, as the results are correlational and not causal, it may be that, as teachers engage more in professional development activities, they encourage more positive teacher-to-teacher interactions in their school