The Effect of Dual Language Immersion Programs on Student Outcomes

Dual Language Immersion (DLI) programs are schools or classrooms within schools that educate students in two languages: English and a target language. DLI programs in Georgia have proliferated in recent years to include 66 programs that reach across 14 school districts as of school year (SY) 2018-19. We partner with two metro-Atlanta school districts to study the impact of access to early-grade DLI programs using data from five cohorts of DLI admission lotteries across 10 DLI programs. This is the largest rigorous analysis of the academic impacts of access to DLIs in Georgia. On average, we find that students with access to DLI programs via enrollment lotteries have higher reading and math test scores by approximately 0.1 standard deviations compared to students who applied but did not gain access. Our results on the impact of DLI access on test scores are comparable in magnitude to the effect of having an experienced teacher

The Effect of Dual Language Immersion Programs on Student Outcomes

Dual Language Immersion (DLI) programs are schools or classrooms within schools that educate students in two languages: English and a target language. DLI programs in Georgia have proliferated in recent years to include 66 programs that reach across 14 school districts as of school year (SY) 2018-19. We partner with two metro-Atlanta school districts to study the impact of access to early-grade DLI programs using data from five cohorts of DLI admission lotteries across 10 DLI programs. This is the largest rigorous analysis of the academic impacts of access to DLIs in Georgia. On average, we find that students with access to DLI programs via enrollment lotteries have higher reading and math test scores by approximately 0.1 standard deviations compared to students who applied but did not gain access. Our results on the impact of DLI access on test scores are comparable in magnitude to the effect of having an experienced teacher.https://scholarworks.gsu.edu/gpl_reports/1035/thumbnail.jp

Effects of an Intensive English Program on Students\u27 Math and English Scores

We estimate the academic impacts of eligibility for and participation in an intensive English program aimed at English Learners (ELs) with very low English proficiency. The program is a short-term intervention to introduce students to basic English skills—academic and social—before they transfer to their neighborhood school. Our results indicate that ELs who are eligible for the program have lower English Language Arts (ELA) achievement in the short term, relative to ELs who receive traditional English as a Second Language (ESL) instruction. These findings are concentrated among older ELs. In subsample analyses, however, we find that refugee ELs who are eligible for the program have higher ELA and math achievement in the short term.https://scholarworks.gsu.edu/gpl_reports/1023/thumbnail.jp

Effects of an Intensive English Program on Students\u27 Math and English Scores

We estimate the academic impacts of eligibility for and participation in an intensive English program aimed at English Learners (ELs) with very low English proficiency. The program is a short-term intervention to introduce students to basic English skills—academic and social—before they transfer to their neighborhood school. Our results indicate that ELs who are eligible for the program have lower English Language Arts (ELA) achievement in the short term, relative to ELs who receive traditional English as a Second Language (ESL) instruction. These findings are concentrated among older ELs. In subsample analyses, however, we find that refugee ELs who are eligible for the program have higher ELA and math achievement in the short term

Refugee Students and Peer Effects

A snapshot of the student population in the school district in our study reveals that in 2016 there were approximately 3,300 refugee students across all grades (K-12). Thus, refugee students made up roughly 3 percent of the total student population in the district. On average, there were about 250 refugee students per grade, with significant variation across grades. For example, while only 2 percent of first-graders were refugees, this proportion climbs to 5 percent among ninth-graders. Refugee students in the district come from a variety of countries and enter with varying language skills. In 2016, over 18 countries were represented among the refugee population. The top country of birth for refugee students in the district was Burma (Myanmar), followed by Ethiopia, The Democratic Republic of Congo, Iraq, and Bhutan. Approximately 26 percent of refugee students did not receive English as a Second Language (ESL) services.https://scholarworks.gsu.edu/gpl_reports/1025/thumbnail.jp

Refugee Students and Peer Effects

A snapshot of the student population in the school district in our study reveals that in 2016 there were approximately 3,300 refugee students across all grades (K-12). Thus, refugee students made up roughly 3 percent of the total student population in the district. On average, there were about 250 refugee students per grade, with significant variation across grades. For example, while only 2 percent of first-graders were refugees, this proportion climbs to 5 percent among ninth-graders. Refugee students in the district come from a variety of countries and enter with varying language skills. In 2016, over 18 countries were represented among the refugee population. The top country of birth for refugee students in the district was Burma (Myanmar), followed by Ethiopia, The Democratic Republic of Congo, Iraq, and Bhutan. Approximately 26 percent of refugee students did not receive English as a Second Language (ESL) services

Optimization of the Superconducting Linear Magnetic Bearing of a Maglev Vehicle

Considering the need for cost/performance prediction and optimization of superconducting maglev vehicles, we develop and validate here a 3D finite element model to simulate superconducting linear magnetic bearings. Then we reduce the 3D model to a 2D model in order to decrease the computing time. This allows us to perform in a reasonable time a stochastic optimization considering the superconductor properties and the vehicle operation. We look for the permanent magnet guideway geometry that minimizes the cost and maximizes the lateral force during a displacement sequence, with a constraint on the minimum levitation force. The displacement sequence reproduces a regular maglev vehicle operation with both vertical and lateral movements. For the sake of comparison, our reference is the SupraTrans prototype bearing. The results of the optimization suggest that the bearing cost could be substantially reduced, while keeping the same performances as the initial design. Alternatively, the performances could be significantly improved for the same original cost

Diversity of Bacillus-like organisms isolated from deep-sea hypersaline anoxic sediments

Abstract Background The deep-sea, hypersaline anoxic brine lakes in the Mediterranean are among the most extreme environments on earth, and in one of them, the MgCl2-rich Discovery basin, the presence of active microbes is equivocal. However, thriving microbial communities have been detected especially in the chemocline between deep seawater and three NaCl-rich brine lakes, l'Atalante, Bannock and Urania. By contrast, the microbiota of these brine-lake sediments remains largely unexplored. Results Eighty nine isolates were obtained from the sediments of four deep-sea, hypersaline anoxic brine lakes in the Eastern Mediterranean Sea: l'Atalante, Bannock, Discovery and Urania basins. This culture collection was dominated by representatives of the genus Bacillus and close relatives (90% of all isolates) that were investigated further. Physiological characterization of representative strains revealed large versatility with respect to enzyme activities or substrate utilization. Two third of the isolates did not grow at in-situ salinities and were presumably present as endospores. This is supported by high numbers of endospores in Bannock, Discovery and Urania basins ranging from 3.8 × 105 to 1.2 × 106 g-1 dw sediment. However, the remaining isolates were highly halotolerant growing at salinities of up to 30% NaCl. Some of the novel isolates affiliating with the genus Pontibacillus grew well under anoxic conditions in sulfidic medium by fermentation or anaerobic respiration using dimethylsulfoxide or trimethylamine N-oxide as electron acceptor. Conclusion Some of the halophilic, facultatively anaerobic relatives of Bacillus appear well adapted to life in this hostile environment and suggest the presence of actively growing microbial communities in the NaCl-rich, deep-sea brine-lake sediments. </jats:sec