Beyond the Spoken Word: Examining the Nature of Teacher Gesturing in the Context of an Elementary Engineering Curriculum for English-Learner Students

Our research team performed an exploratory analysis of teacher gesturing via a case study of an elementary teacher. We focused on gesturing, a practice found to support both bilingual English learner students’ linguistic development and mathematics achievement, during the teacher’s engineering and science lessons. The research team systematically analyzed teacher video data using McNeill’s gestural dimensions framework and found variation of gesturing types and rates when comparing engineering and baseline science lessons. Additionally, specific types of teacher-gestures appear to be associated with either behavioral or classroom management practices, procedural instructions, and discussion facilitation. We suggest that teacher-gestures such as these have the potential to facilitate bilingual English learners’ language acquisition, while also developing their STEM literacy in general and engineering capacity in particular. Further exploration of teacher-gestures in elementary engineering curricula could lead to an integrated STEM pedagogy that incorporates gesturing as a fundamental teaching strategy, bridging STEM instruction with linguistically responsive instructional practices.Educatio

Particles adsorbed at various non-aqueous liquid-liquid interfaces

Particles adsorbed at liquid interfaces are commonly used to stabilise water-oil Pickering emulsions and water-air foams. The fundamental understanding of the physics of particles adsorbed at water-air and water-oil interfaces is improving significantly due to novel techniques that enable the measurement of the contact angle of individual particles at a given interface. The case of non-aqueous interfaces and emulsions is less studied in the literature. Non-aqueous liquid-liquid interfaces in which water is replaced by other polar solvents have properties similar to those of water-oil interfaces. Nanocomposites of non-aqueous immiscible polymer blends containing inorganic particles at the interface are of great interest industrially and consequently more work has been devoted to them. By contrast, the behaviour of particles adsorbed at oil-oil interfaces in which both oils are immiscible and of low dielectric constant (ε < 3) is scarcely studied. Hydrophobic particles are required to stabilise these oil-oil emulsions due to their irreversible adsorption, high interfacial activity and elastic shell behaviour

Characterization of the killer toxin KTCf20 from wickerhamomyces anomalus, a potential biocontrol agent against wine spoilage yeasts

Wickerhamomyces anomalus Cf20 secretes the killer toxin KTCf20 that inhibits several wine spoilage yeasts of the species Pichia guilliermondii, P. membranifaciens, Brettanomyces bruxellensis and Dekkera anomala. KTCf20 binds cell wall extracts from the sensitive target P. guilliermondii Cd6; however, this capacity was lost when cell wall extracts were pre-treated with fungal β-glucanase. Pustulan and laminarin inhibited killer activity, suggesting that β-1,3 and β-1,6-glucans may be the putative binding sites for KTCf20 on the cell wall of sensitive cells. The toxin was produced and showed to be stable and highly active at physicochemical conditions suitable for winemaking process. In addition, the strain Cf20 is compatible with Saccharomyces cerevisiae in co-culture conditions being potential its application in a mixed starter culture. These data suggest that W. anomalus Cf20 and/or KTCf20 are promising biocontrol agents against spoilage yeasts during wine-making process.Fil: Fernandez de Ullivarri, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Mendoza, Lucia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Raya, Raul Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

On-site approximation for spin-orbit coupling in LCAO density functional methods

We propose a computational method that simplifies drastically the inclusion of spin-orbit interaction in density functional theory implemented on localised atomic orbital basis sets. Our method is based on a well-known procedure for obtaining pseudopotentials from atomic relativistic 'ab initio' calculations and on an on-site approximation for the spin-orbit matrix elements. We have implemented the technique in the SIESTA code, and we show that it provides accurate results for the overall band structure and splittings of group IV and III-IV semiconductors as well as for 5d metals.Comment: 8 pages, 4 figures. Published in J. Phys.: Condens. Matter 18 7999-8013, 2006. Some errata correcte