Texas Christian University

About: Texas Christian University is a education organization based out in Fort Worth, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 3245 authors who have published 8258 publications receiving 282216 citations. The organization is also known as: TCU & Texas Christian University, TCU.

The expertise of literacy teachers: A continuum from preschool to Grade 5

Abstract: Research has demonstrated that teaching expertise makes a significant difference in the rate and depth of students' literacy growth, and that highly effective educators share similar characteristics (Block, 2001a; Bond & Dykstra, 1967/1997; International Reading Association, 2000; Pressley, Allington, Wharton-McDonald, Block, & Morrow, 2001; Ruddell, 1997). The National Reading Research Panel (NRRP, 1999) and IRA (2000) recommended that “educators seek out teachers who best exemplify solid teaching, support their work, and consider their successes” (NRRP, p. 20). The purpose of this study was to identify the qualities of teaching expertise that distinguished highly effective instruction at different grade levels. The study occurred in four phases. In Phase I, 647 directors of literacy instruction, in K-12 institutions from seven English-speaking countries, analyzed highly effective instruction in action from preschool to Grade 5 through case study point-by-point Delphi procedures. In Phase II, the resultant 1,294 characteristics of teaching expertise were dimensionalized into 475 categories and interrater reliabilities were computed. In Phase III, 11 prominent researchers from the U.S., Canada, and Australia cross-validated the data. In Phase IV, the authors summarized the five most distinctive qualities per grade level, compared characteristics across grades, and analyzed commonalities and differences between literacy directors' and researchers' rankings. Preschool to Grade 5 literacy teachers were distinguished from one another by 44 indices of teaching expertise. Applications of these data for research, policy, and practice were described. La investigacion ha demostrado que la aptitud didactica influye significativamente en la velocidad y profundidad del desarrollo de la alfabetizacionen los estudiantes; asimismo, los docentes muy eficaces comparten caracteristicas similares (Block, 2001a; Bond & Dykstra, 1967/1997; International Reading Association, 2000; Pressley, Allington, Wharton-McDonald, Block & Morrow, 2001; Ruddell, 1997). El Panel Nacional de Investigacion en Lectura (NRRP, 1999) y la IRA (2000) recomendaron que “los educadores busquen docentes que representenuna didactica solida, den sustento a su trabajo y consideren sus logros” (NRRP, p. 20). El proposito de este estudio fue identificar las cualidades de las aptituden didacticasque distinguieron la ensenanza efectiva en diferentes niveles escolares. El estudio se llevo a cabo en cuatro fases. En la Fase I, seiscientos cuarenta y siete directores de instruccionen alfabetizacion, en instituciones K-12 de siete paises de habla inglesa, analizaron las didacticas efectivas en accion, desde el nivel inicial hasta 5° grado, a travesde procedimientos Delphi de estudios de caso. En la Fase II, el resultante, 1294 caracteristicas de aptitud didactica, se dimensionalizaron en 475 categorias y se computo laconfiabilidad entre ellas. En la Fase III, once destacados investigadores de los Estados Unidos, Canada y Australia validaron los datos. En la Fase IV, los autores resumieron las cinco cualidadesmas prominentes por nivel escolar, compararon las caracteristicas entre grados y analizaron las similitudes y diferencias entre los rangos asignados por los directores y los investigadores. Los docentes de nivel inicial a 5° grado se distinguieron entre si por cuarenta y cuatro indices de aptitud didactica. Se describieron las aplicaciones de estos datos a la investigacion, las politicas educativas y la practica. Die Forschung hat gezeigt, das das Unterrichtsfachwissen einen bedeutenden Unterschied in der Steigerung und Vertiefung bei Leseund Schreibleistungender Schuler macht, und das hochgradig effektive Erzieher derartige Charakteristiken teilen (Block, 2001a; Bond & Dykstra, 1967/1997; International Reading Association, 2000; Pressley, Allington, Wharton-McDonald, Block, & Morrow, 2001; Ruddell, 1997). Der Fachausschus National Reading Research Panel (NRRP, 1999) und IRA (2000) empfahl, das “Erzieher jene Lehrer heraussuchen, diefundiertes Unterrichten musterhaft ausuben, die ihre Arbeit fordern und ihre Fortschritte uberdenken” (NRRP, S. 20). Der Zweck dieser Studie war es, die Qualitaten des Unterrichtsfachwissenszu identifizieren, welche sich durch besonders wirksame Anwendung in den unterschiedlichen Klassenstufen hervorhoben. Die Studie erfolgte in vier Phasen. In Phase I analysierten 647 Direktoren furSpracherziehung in K-12 Schulen aus sieben Englisch sprechenden Landern hochgradig wirksam angewandte Unterrichtsanweisungen aus der Vorschule bis zur 5. Klasse nach den Punkt fur Punkt befolgtenDelphi Methoden. In Phase II wurden die daraus resultierenden 1294 Charakteristiken des Unterrichtsfachwissens in 475 Kategorien unterteilt und die gegenseitigen Bezugswerte wurden nach ihrer Verlaslichkeithochgerechnet. In Phase III verifizierten elf prominente Sprachforscher aus den USA, Kanada und Australien die Daten. In Phase IV fasten die Autoren die funf am meisten herausragenden Qualitatenpro Unterrichtsstufe zusammen, verglichen deren Charakteristiken quer durch die Stufenbewertungen und analysierten Gemeinsamkeiten und Unterschiede zwischen den Bewertungen der Direktoren und der Forscherim Sprach-/Rechtschreibbereich. Die Sprach/Rechtschreiblehrer in der Vorschule bis zur 5. Klasse unterschieden sich durch 44 Indices des Unterrichtsfachwissens voneinander. Anwendungsbereiche dieser Datenin der Forschung, bei der Auslegung und in der Praxis wurden beschrieben. La recherche a montre que la competence professionnelle des enseignants a des effets significatifs en quantiteet en profondeur sur le developpement de la litteratie des eleves, et que les educateurs tres efficaces ont des caracteristiques communes (Block, 2001a;Bond & Dykstra, 1967/1997; International Reading Association, 2000; Pressley, Allington, Wharton-McDonald, Block & Morrow, 2001; Ruddell, 1997). Le National Reading Research Panel (NRRP, 1999) etl'IRA (2000) ont recommande que « les educateurs decouvrent des enseignants representant le mieux ce qu'est un enseignement solide, qu'ils soutiennent leur travail et reflechissenta leurs reussites » (NRRP, p.20). Le but de cette etude est d'identifier les caracteristiques de la competence pedagogique qui caracterisent un enseignementefficace aux differents niveaux de la scolarite. L'etude s'est deroulee en quatre temps. Au temps I, six cent quarante sept directeurs d'enseignement de la litteratie, dans des institutions allant de la Maternelle a la 12° annee de sept pays anglophones, ont analyse un enseignement tres efficace en action, de la Maternelle a la 5°annee, au moyen d'analyses de cas point par point suivant les procedures de Dolphi. Au temps II, les 1294 caracteristiques de competence pedagogique en resultantont ete classees en 475 categories et on a calcule la fidelite inter-juges. A la phase III, onze chercheurs eminents des Etats-Unis, du Canada, et d'Australie ont effectue une validation croisee des resultats. A la phase IV, les auteurs ont resume les cinq caracteristiques les plus distinctives parniveau scolaire, compare ces caracteristiques d'un niveau a l'autre, et analyse ce qui est commun et ce qui differe entre les classements faits par des responsables enlitteratie et des chercheurs. Les enseignants de litteratie de la Maternelle a la 5° annee se differencient les uns des autres par quarante quatre indices de competencepedagogique. On presente enfin les retombees de ces resultats pour la recherche, la politique, et la pratique.

Chirality Inversion of CdSe and CdS Quantum Dots without Changing the Stereochemistry of the Capping Ligand

Abstract: L-cysteine derivatives induce and modulate the optical activity of achiral cadmium selenide (CdSe) and cadmium sulfide (CdS) quantum dots (QDs). Remarkably, N-acetyl-L-cysteine-CdSe and L-homocysteine-CdSe as well as N-acetyl-L-cysteine-CdS and L-cysteine-CdS showed "mirror-image" circular dichroism (CD) spectra regardless of the diameter of the QDs. This is an example of the inversion of the CD signal of QDs by alteration of the ligand's structure, rather than inversion of the ligand's absolute configuration. Non-empirical quantum chemical simulations of the CD spectra were able to reproduce the experimentally observed sign patterns and demonstrate that the inversion of chirality originated from different binding arrangements of N-acetyl-L-cysteine and L-homocysteine-CdSe to the QD surface. These efforts may allow the prediction of the ligand-induced chiroptical activity of QDs by calculating the specific binding modes of the chiral capping ligands. Combined with the large pool of available chiral ligands, our work opens a robust approach to the rational design of chiral semiconducting nanomaterials.

The influence of host plant variation and intraspecific competition on oviposition preference and offspring performance in the host races of Eurosta solidaginis

Abstract: Summary 1. A series of experiments was conducted to measure the impact of plant genotype, plant growth rate, and intraspecific competition on the oviposition preference and offspring performance of the host races of Eurosta solidaginis (Diptera: Tephritidae), a fly that forms galls on Solidago altissima and Solidago gigantea (Asteraceae). Previous research has shown that both host races prefer to oviposit on their own host plant where survival is much higher than on the alternate host plant. In this study, neither host race showed any relationship between oviposition preference and offspring performance in choosing among plants of their natal host species. 2. The larval survival of both host races differed among plant genotypes when each host race oviposited on its natal host species. In one experiment, altissima host race females showed a preference among plant genotypes that was not correlated with offspring performance on those genotypes. In all other experiments, neither the altissima nor gigantea host race demonstrated a preference for specific host plant genotypes. 3. Eurosta solidaginis had a preference for ovipositing on rapidly growing ramets in all experiments, however larval survival was not correlated with ramet growth rate at the time of oviposition. 4. Eurosta solidaginis suffered high mortality from intraspecific competition in the early larval stage. There was little evidence, however, that females avoided ovipositing on ramets that had been attacked previously. This led to an aggregated distribution of eggs among ramets and strong intraspecific competition. 5. There was no interaction among plant genotype, plant growth rate, or intraspecific competition in determining oviposition preference or offspring performance.