Traces to Entrenchment: A Mixed Methods Study Examining the Use of Reading and Writing to Facilitate Lexical Sequence Acquisition Among Bilingual Learners and Factors Influencing Their Language Learning

Informed by entrenchment and usage-based theories, this mixed methods study, modeled after Riazi\u27s mixed methods fully integrated design, examined how reading and writing may be used to facilitate lexical sequence acquisition for high school bilingual learners. The study compared the efficacy of two interventions on increasing the depth of knowledge of lexical sequences: a reading intervention requiring the reading of short informational texts embedded with eight target lexical sequences and a writing intervention requiring participants to follow the readings with the intentional use of target sequences in writing. A repeated measures factorial ANOVA found no impact of gender or first language on results; both groups made statistically significant gains on depth of knowledge during both interventions with large effect sizes, and they retained gains three to four weeks later. However, reading was found to be more impactful for one group, whereas reading and writing was found to be more impactful for the second group. Subsequent analyses of written responses by participants coupled with a repeated measures ANOVA measuring the acquisition of individual sequences demonstrated that participants were more likely to acquire and use some lexical sequences than others. Data from semi-structured interviews from 12 participants were analyzed through the lens of Anthias’ multilevel model of intersectionality to determine factors influencing intervention results as well as English learning generally. Results of this qualitative strand revealed that the requirement to read twice weekly led reading to become a habit for some participants, that text interest impacted some participants’ motivation to comprehend the text, and that interlinear glossing (providing synonyms above target sequences) was helpful for reading comprehension. Gender and L1 were found to influence learning through the long-lasting impact of bullying, which often led females and those with perceived accents to refrain from speaking English even years after bullying occurred. Other salient findings suggest that the employment of high school students may be underreported and that implicit teacher bias may impact the schooling of some bilingual learners. One LGBTQ bilingual learner narrative provided a positive example of empowerment despite the bullying of others. Several recommendations for research, policy, and teaching practices are discussed

Dynamic crystallization experiments on chondrule melts in reduced gravity

Chondrules crystallized during the earliest formational history of the solar system; and, if crystal settling and flotation are indicators of crystallization in the presence of gravity, they formed without the influence of gravity. In fact, attempts to duplicate the crystallization history of chondrules in the laboratory have met with limited success, because of the difficulty of comparing objects formed under the influence of gravity with objects that did not. These comparisons are difficult because there are several recognized features introduced by the presence of gravity and no doubt some which are not yet recognized. As a result there are several microscale and macroscale aspects of chondrule petrology which are difficult to understand quantitatively. Most of the features relate to the settling or flotation of early formed crystals. The proposed experiments are briefly described

Crystallization of the Zagami Shergottite: An Experimental Study

Spherulites are usually rounded or spherical objects found in rhyolitic obsidian. They usually comprise acicular crystals of alkali feldspar that radiate from a single point. The radiating array of crystalline fibers typically have a similar crystallographic orientation such that a branch fiber departs slightly but appreciably from that of its parent fiber. Individual fibers range from 1 to several micrometers in diameter. The spherulites most likely form by heterogeneous nucleation on microscopic seed crystals, bubbles, or some other surface at high degrees of supercooling. They grow very rapidly stabilizing their fibrous habit and typically range in size from microscopic to a few cm in diameter

NASA Desert RATS 2010: Preliminary Results for Science Operations Conducted in the San Francisco Volcanic Field, Arizona

The National Aeronautics and Space Administration (NASA) is working with international partners to develop the space architectures and mission plans necessary for human spaceflight beyond earth orbit. These mission plans include the exploration of planetary surfaces with significant gravity fields. The Apollo missions to the Moon demonstrated conclusively that surface mobility is a key asset that improves the efficiency of human explorers on a planetary surface. NASA's Desert Research and Technology Studies (Desert RATS) is a multi-year series tests of hardware and operations carried out annually in the high desert of Arizona. Conducted since 1998, these activities are designed to exercise planetary surface hardware and operations in relatively harsh climatic conditions where long-distance, multi-day roving is achievabl

An experimental study of trace element partitioning between perovskite, hibonite and melt: Equilibrium values

The presence of perovskite (CATiO3) and hibonite (Ca Al12O19) within different regions of Calcium-, Aluminum-rich Inclusions (CAI) and the trace element concentrations of these minerals in each circumstance, constrain models of precursor formation, nebular condensation, the thermal history of inclusions with relict perovskite and hibonite, and the formation of the Wark-Lovering rim. At present mineral/melt partition coefficient data for hibonite are limited to a few elements in simple experimental systems, or to those derived from hibonite-glass pairs in hibonite/glass microspherules. Similarly, there is only limited data on perovskite D that are applicable to meteorite compositions. Apart from the importance of partitioning studies to meteorite research, D values also are invaluable in the development of thermodynamic models, especially when data is available for a large number of elements that have different ionic charge and radii. In addition, study of the effect of rapid cooling on partitioning is crucial to our understanding of meteorite inclusions. To expand our knowledge of mineral/melt D for perovskite and hibonite, a study was instituted where D values are obtained in both equilibrium and dynamic cooling experiments. As an initial phase of this study mineral/melt D was measured for major elements (Ca, Mg, Al, Ti, and Si), 15 rare earth elements (La-Lu) and 8 other elements (Ba, Sr, U, Th, Nb, Zr, Hf, and Ge) in perovskite and hibonite grown under equilibrium conditions, in bulk compositions that are respectively similar to Compact Type A (CTA) CAI and to a hibonite/glass microspherule. Experimental mixes were doped with REE at 20-50x chondritic (ch) abundances, Ba at 50 ppm, Sr, Hf, Nb, and Zr at 100 ppm and, U and Th at 200 ppm. Trace element abundances were measured with the PANURGE ion microprobe. Major element compositions were obtained by electron microprobe analysis