Mothers\u27 prosodie features: Strategies to guide young children\u27s understanding of book language

Mothers use prosody to engage children during book reading. Thus, prosody may contribute to children\u27s literacy. The purpose of this study was to describe how twenty-five mothers across children\u27s age groups (6-month olds, 12-month-olds, 18-month-olds, 24-month-olds, and 4-year-olds) used prosody, specifically pitch and stress variations, while reading with their children. Common speech samples from the readings of two different texts (narrative and expository) were analyzed. In addition, the mothers were questioned about their use of expressive language while reading. Patterns from the data showed that the mothers of the 6-month-olds did not vary their speech as often. They used the book reading event to teach basic book reading concepts and to play. The narrative text showed the use of more expressive language. The mothers\u27 intent was to guide children\u27s understanding of the complexities of the story. All the mothers used pitch and stress in conjunction with other book reading strategies to scaffold the texts for their children

Addressing Disciplinary Literacy: An Examination of Teachers’ Instruction in First Grade

Disciplinary literacy instruction during kindergarten through second grade enables students to begin developing facility with consuming, producing, and learning from texts in academic disciplines across their school careers and for full civic participation. Extant intervention studies and descriptions of practice in the primary grades offer understanding of disciplinary literacy instruction when it is enacted with researchers’ help and/or by teachers with expertise in disciplinary literacy. To address disciplinary literacy in the primary grades, insight into what primary teachers focus on and how they support students’ disciplinary literacy learning during their naturally-occurring instruction is needed. This exploratory collective case study examined the disciplinary literacy learning opportunities available in first-grade teachers’ instruction. Participants included four teachers in four elementary schools situated in a large city in the Midwest. Audio records and field notes were collected over a period of five months during teachers’ literacy instruction. Open coding, progressive refinement of codes, and categorical analyses revealed limited instructional emphasis on disciplinary literacy. When learning opportunities were observed, teachers’ foci and support centered on the social foundations of disciplinary literacy and included sharing of information and student practice. Also, problematic disciplinary literacy learning opportunities were noted. This study underscores the urgent need for additional attention to disciplinary literacy as it is situated within the primary grades, with particular import for how first-grade teachers enact disciplinary literacy instruction

Professional Development and Educational Policy: A Comparison of Two Fields in Education

The purpose of this paper is to compare two fields of research related to school reform: professional development and educational policy. A content analysis of the literature in both fields revealed two areas where they align (i.e., a focus on teachers’ professional development and the idea that change takes time) as well as two areas where there are differences (i.e., theoretical grounding of each field and planning for teachers’ learning). Considerations for successful school reform are suggested

Reply

The authors respond to Hoffman et al. (2001), who acknowledged that methane may have played an important role in unusual events associated with Neoproterozoic glaciation, but questioned the authors' permafrost gas hydrate hypothesis for 13C-depleted cap carbonate formation. The critique focused on three issues: (1) an interpretation for tube structures in cap carbonates unrelated to gas migration; (2) the absence of a suitable source for methane gas; and (3) the degree of 13C depletion in sheet-crack cements

Reply

The authors address additional comments on their hypothesis for the origin of Neoproterozoic postglacial cap carbonates and their isotopic excursions

Optimal control for halo orbit missions

This paper addresses the computation of the required trajectory correction maneuvers (TCM) for a halo orbit space mission to compensate for the launch velocity errors introduced by inaccuracies of the launch vehicle. By combiningdynamical systems theory with optimal control techniques, we produce a portrait of the complex landscape of the trajectory design space. This approach enables parametric studies not available to mission designers a few years ago, such as how the magnitude of the errors and the timingof the first TCM affect the correction ΔV. The impetus for combiningdynamical systems theory and optimal control in this problem arises from design issues for the Genesis Discovery mission being developed for NASA by the Jet Propulsion Laboratory

Are Proterozoic Cap Carbonates and Isotopic Excursions a Record of Gas Hydrate Destabilization Following Earth’s Coldest Intervals

Regionally persistent, thin intervals of carbonate rock directly and ubiquitously overlie Proterozoic glacial deposits on almost every continent, and are commonly referred to as cap carbonates. Their unusual facies, stratigraphically abrupt basal and upper contacts, and strongly negative carbon isotopic signature (δ13C values between ∼0‰ and −5‰) suggest a chemical oceanographic origin, the details of which remain unresolved. Here we propose that these enigmatic deposits are related to the destabilization of gas hydrate in terrestrial permafrost following rapid postglacial warming and flooding of widely exposed continental shelves and interior basins. Supporting evidence for this hypothesis includes (1) the common occurrence within the cap carbonates of unusual fabrics, similar to those produced by cold methane seeps; (2) a distinctive time evolution for the carbon isotopic excursions indicative of a pulse addition of isotopically depleted carbon to the ocean- atmosphere system; and (3) agreement between mass-balance estimates of carbon released by hydrate destabilization and carbon buried in the cap carbonate. We infer that during times of low-latitude glaciation, characteristic of the Neoproterozoic, gas hydrates may have been in greater abundance than at any other time in Earth history

Transforming Schools: The Power of Teachers’ Input in Professional Development

Recent legislative actions have mandated the professional development of teachers in hopes of improved student achievement. However, research has shown that mandated professional development most usually does not lead to a positive outcome. This article describes three aspects that have been identified as contributing to the transformation of instruction in schools: school context, role of the administrator, and cohesion between professional development and needs of students/teachers. Mezirow’s adult learning theory supports these important aspects of school reform and has implications for planning and developing educators’ professional development

Considering a Neoproterozoic Snowball Earth

P. F. Hoffman et al. and N. Christie-Blick et al. discuss Hoffman et al.'s paper that "developed a modified 'snowball Earth' hypothesis (2) to explain the association of Neoproterozoic low-latitude glaciation with the deposition of 'cap carbonate' rocks bearing highly depleted carbon isotopic values (δ13C ≤ −5‰). According to Hoffman et al., the ocean became completely frozen over as a result of a runaway albedo feedback, and primary biological productivity collapsed for an interval of geological time exceeding the carbon residence time (greater than 105 years). During this interval, continental ice cover is inferred to have been thin and patchy owing to the virtual elimination of the hydrological cycle.