Identifying and Encouraging Math In Children\u27s Out-of-School Activities In the Rural Lowcountry of South Carolina

Research shows that children of different backgrounds and cultures learn and perform differently in mathematics despite similar intelligence levels and mathematics instruction (Alvarez & Bali, 2004). Ethnomathematics strives to explore and explain such phenomena in terms of the complex role culture plays in one\u27s background experiences and perceptions that influence cognition and how school is experienced (Ascher, 1991; Barton, 1996; Bishop, 1994; D\u27Ambrosio, 1994). The importance of recognizing and utilizing the mathematical concepts imbedded in students\u27 everyday activities is stressed in the field of ethnomathematics (Ascher, 1991; Bishop, 1994; Presmeg, 1998). In order to relate students\u27 out-of-school experiences to content learning for the most accessible, effective math instruction, educators must have a deep understanding of students\u27 experiences and how mathematical concepts relate to these. This qualitative research aims to shed light on the out-of-school activities that a group of 4th grade students from the same rural area of the Lowcountry of South Carolina participate. The manner in which the students participate in these activities, including any use of mathematical concepts, was explored. A technique called dialogue journaling, in which students write about their out-of-school experiences with the teacher responding with written questions and comments (Peyton, 1993), was tailored for the purposes of math education. This dialogue journaling was used to learn about students\u27 activities, any utilization of mathematical concepts involved in these activities, and students\u27 perceptions of the embedded mathematics. The journals were also explored as a meansfor classroom teachers to encourage students to apply more mathematical concepts in their out-of-school activities. It was found these students participate in a large range of daily activities. Activities that were common for many of the students included watching television, riding bikes, playing on the computer, playing video games, sports, horseback riding, hunting, riding four-wheelers, golf carts, and go-carts. Some activities were unique to individuals such as observing spiders and modeling in fashion shows. Mathematical ideas embedded in the manner in which these students participate in their activities began to emerge. These concepts include simple counting, skip counting, patterns, using money, measuring and estimating distance and weight, division, and probability. The students did not readily perceive themselves as using many mathematical ideas during their activities. Mathematical ideas that were recognized by students include simple counting, using money, and measuring. Dialogue journals proved to be an efficient strategy for learning about activities in which students participate, how they participate in such activities, and their perceptions of these activities. The majority of the students liked having written conversations with their teacher in the dialogue journals, but did not like having to respond in the journals for homework. Dialogue journals were able to be used to encourage and push students to apply more mathematical thinking when considering their daily activities in some cases, but not all

VUV/EUV ionising radiation and atoms and ions: dual laser plasma investigations

The interaction of ionising radiation with atoms and ions is a key fundamental process. This report concentrates on studies of photoexcitation/photoionisation using laser-produced plasmas as continuum sources and synchronised laser plasma plumes to provide the absorbing atom or ion species. Examples from studies of the interaction of ionising radiation with atoms and ions ranging from few-electron atomic and ionic systems to the many-electron high atomic number actinides are reviewed and illustrate the advantages and limitations of the Dual Laser Plasma technique

Pouvoir entre enseignante et doctorante : utilisation de données de recherche et signature scientifique

Cette étude de cas fictive met en évidence différentes pratiques d’utilisation de données de recherche dans le cadre d’une collaboration entre enseignante-chercheure et  doctorante. Elle vise à mettre au jour les difficultés et enjeux éthiques d’une telle collaboration et particulièrement les défis liés à la signature scientifique et à l’utilisation des données à l’issue de la recherche

Trends in autoionization of Rydberg states converging to the 4s threshold in the Kr-Rb⁺-Sr²⁺ isoelectonic sequence: theory and experiment

We have measured the photoabsorption spectra of the Kr-like ions Rb+ and Sr2+ at photon energies corresponding to the excitation of 4s-np resonances using, the dual laser plasma photoabsorption technique. Dramatic changes in the line profiles, with increasing ionization and also proceeding along the Rydberg series of each ion, are observed and explained by the trends in 4s-transition amplitudes computed within a framework of configuration-interaction Pauli-Fock calculations. Total photoionization cross sections show very good agreement with relative absorption data extracted from the measured spectra

Even-parity autoionizing states in the extreme-ultraviolet photoabsorption spectra of Mg, Al⁺, and Si²⁺

The dual-laser-produced plasma (DLP) photoabsorption technique has been used to study 2p→3s excitations in the isoelectronic species Mg, Al+, and Si2+ prepared in the excited configuration 2p63s3p. The autoionizing upper states belong to the 2p53s23p even-parity configuration. The versatility of the technique is demonstrated through a careful combination of space- and time-resolved photoabsorption scans. Plasma conditions optimized for the observation of the inaccessible parity regime were successfully reproduced along the isoelectronic sequence of interest. All the observed transitions were interpreted with the help of multiconfigurational atomic structure calculations. In the case of magnesium, the photoabsorption data are compared with the ejected-electron spectra excited by low-energy electron impact of Pejcev et al. [J. Phys. B 10, 2389 (1977)]