An Animal Model of MYC-Driven Medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB, and identify a novel model that can be used to test therapies for this devastating disease

Bioassimilation, Burial, and Sediment Denitrification at Shallow-water and Deep-water Oyster Reefs in Two Louisiana Estuaries

The eastern oyster (Crassostrea virginica) and the reefs they create are highly valued for the ecosystem services they provide to coastal estuaries. Recently, their capacity to contribute to nutrient mitigation has spurred interest as researchers have identified 3 mechanisms directly or indirectly associated with oyster reef habitat. This study measured bioassimilation, long-term nutrient burial, and oyster-mediated denitrification in shallow-water (\u3c 1 m water depth) and deep-water (\u3e 1 m water depth) oyster reefs located in two southern Louisiana estuaries. Carbon and nitrogen assimilated into shell and tissue of small (\u3c 75 mm) and large (\u3e 75 mm) oysters was within the range of previous studies but was found to be less influenced by reef type, and more dependent on location specific factors and reproductive status. Post-spawning oysters were found to have higher percent nitrogen content in tissue compared to pre-spawning populations, likely a result of the loss of gametes and increase in feeding related activities during the post-spawn season. Carbon and nitrogen burial rates at oyster reefs ranged from 23.02-57.69 g m-2 yr-1 and 1.09-4.49 g m-2 yr-1 respectively and did not exceed that of other habitat types in Louisiana. However, they were considered to be an important source of nutrient mitigation in these estuaries. Shallow-water reefs buried significantly more nitrogen and carbon, which may be attributed to their proximity to the marsh edge and thus greater influx of detrital material. Closed-system ex-situ incubations revealed some of the highest ever recorded sediment denitrification rates at oyster reefs in the United States (\u3e 1000 µmol m-2 hr-1). However, these values were within the range of those documented in Louisiana coastal systems, and similar to those recorded in nearby reference sediments. Variation in denitrification was found to correspond to site and season, rather than the influence of oyster reef habitat. Because the estuaries in this study are a matrix of reefs and soft bottom sediments, oysters may influence nutrient mitigation outside the boundaries of their active reefs. Thus, bioassimilation, burial, and denitrification may not be localized, but instead may resonate across larger areas as determined by historical reef acreage and hydrodynamics. These are among the first estimates for nutrient mitigation at oyster reefs in Louisiana, and indicate the potential of this ecosystem service in our region. Future research should consider site-specific conditions such as nutrient loading rates, oyster density, and active harvest to accurately quantify this ecosystem service across the coastal region of the state

Biofuel Combustion Chemistry: From Ethanol to Biodiesel

Kohse-Höinghaus K, Oßwald P, Cool TA, et al. Biofuel Combustion Chemistry: From Ethanol to Biodiesel. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION. 2010;49(21):3572-3597

Assessment and assimilation: a program for schools challenged with mobility

Student mobility is the process of describing how children move from one school to another for reasons other than promotion. Highly mobile students are defined as students who move six or more times during their school career. Schools that experience the constant flow of students moving in and out struggle with delivering consistent and effective instruction for both the stable and the highly mobile student. The effects that highly mobile students have on academic achievement and accountability have failed to be addressed by education reform initiatives. The results of student mobility continue to go unnoticed and remain a serious problem that impacts all aspects of education reform, contributing to the gap in achievement between the advantaged and disadvantaged. This dissertation examined the effectiveness of the Assessment and Assimilation Program, which was designed to support highly mobile students entering Best Middle School. In the study, student data from Best's highly mobile students (transcripts, discipline reports, and attendance reports) were used to measure the relationship between academic achievement (improved grades), attendance (increased time in school), and discipline (decrease in negative referrals) after attending Assessment and Assimilation at Best Middle School. (Published By University of Alabama Libraries

The effects of self-determination, identification with school, and school climate on middle school students' aspirations for future education

The purpose of this study was to explore the effects of self-determination, identification with school, and school climate on student aspirations for ongoing and future education. This study sought to answer the following research questions: (1) What are the relationships between student self-determination, identification with school, and perceptions of school climate? (2) How do ethnicity, socioeconomic status, gender, and self-determination affect students' aspirations for ongoing and future education? (3) How do ethnicity, socioeconomic status, gender, and identification with school affect students' aspirations for ongoing and future education? And (4) How do ethnicity; socioeconomic status, gender, and school climate affect students' aspirations for ongoing and future education? The first question was answered using bivarate correlation. Questions 2 through 4 were answered using three hierarchical multiple regression procedures. The research design used survey research and quantitative analyses to determine factors that most influence middle school students' aspirations for future education. The unit of analysis was 458 eighth grade students in one southern school system. Survey results provided evidence that the students' demographic variables of gender and ethnicity were significant predictors of their aspirations for future education. Self-determination explained 15% of the variance, identification with school explained 10% of the variance, and climate explained 3% of the variance in students' aspirations for ongoing and future education over and above the effects of ethnicity, gender, and socioeconomic status. This study contributes to the knowledge base by exploring the effects of all three variables: self-determination, identification with school, and school climate on student aspirations for future education. Furthermore, this study offers preliminary evidence of the effects of student self-determination, identification with school, and school culture on student aspirations for future education. Creating a school culture to encourage increased self-determination and identification with school represents an area that is malleable and can result in increased educational aspirations and commitment to academic success. Administrators interested in improving the school culture should focus on early identification of at-risk students and promote program development that encourages active participation from students and families, positive teacher-student relationships, and opportunities for students to develop knowledge and skills that promote a sense of self-determination and identification with school. (Published By University of Alabama Libraries

The attitudes and behaviors of school officials and how they engage parents in trusting relationships in high achieving Title I schools

This study was conducted to understand the behaviors and attitudes displayed by school officials in building trusting relationship with parents in successful Title I schools. Four school sites within the same school district were chosen for this study. The study was a qualitative action research study. Four participants were interviewed at each school site (a total of sixteen participants were interviewed). All interviews were transcribed and coded for common themes. Based on the results of the study, recommendations were made for school officials and school organizations who seek to building trusting relationships with parents. (Published By University of Alabama Libraries

Relationships among teacher quality characteristics and reading and mathematics achievement in Title I schools in the Alabama Black Belt Region

The purpose of this study was to examine relationships existing among teacher quality characteristics and reading and math achievement on the Alabama Reading and Math Test in Title I schools in the Western and Midwestern regions of Alabama. The population identified was 57 schools in 13 school districts (seven feeder schools, five schools with sixth grade only, one school with fifth through sixth grades, and one school with fourth through sixth grades). The sample consisted of 29 schools and 9 school districts and a sample of 284 teachers. This study used descriptive statistics, bivariate (Spearman) correlation, and multiple regression to analyze data to answer three research questions addressing relationships among teachers' pedagogical knowledge, educational background, years of experience, grade level configuration (assignment) and professional development (independent variables), and reading/mathematics achievement (dependent variables) on the Alabama Reading and Math Test. A field test was conducted in a neighboring school district to assist the researcher in evaluating the participants' responses to survey questions, to determine whether the survey questions had the potential to produce the desired data, and to evaluate the wording of the questions on the survey. Particularly, this study verified that teachers' grade level configuration is significantly related to the students' math and reading achievement on the Alabama Reading and Math Test. In the same way, this study also confirmed that teachers' years as a full-time teacher is a significant predictor of student math achievement and teachers' years taught in the public school sector is a significant predictor or student reading achievement. Also, this study confirmed that teachers' professional development components such as Alabama Reading Initiative Training (ARI) is negatively significant to reading achievement on the Alabama Reading and Math Test. These findings were consistently constructed based on statistical analyses, which may have important and practical implications. In effect, such information may be useful for school administrators to continue to examine teacher quality characteristics to determine, which teacher quality characteristics influence student achievement. Furthermore, these findings may guide strategic decisions, mostly those referred to implement policies to improve teacher quality as well as other education policies to motivate high-quality teaching. (Published By University of Alabama Libraries

Mentors' and mentees' perceptions of a system-wide mandated mentoring program for first-year teachers

Throughout the United States school systems are aware of the teacher shortage. The projected need to fill 2.2 million positions by 2010 will increase throughout the educational field, especially in areas of high poverty schools and particular content areas. Therefore, it is crucial to provide the best type of mentoring program to retain the best and brightest teachers in the educational field. The purpose of this mixed method study was to examine the perceptions of first-year teachers and their mentors regarding their school system's mentoring program. Furthermore, this study examined the perceived effects of the program. The results of the study indicated that the mentoring program appeared to be nurturing as perceived by the first-year teachers. Their mentors perceived the program to be beneficial. The recommendations for future studies suggested that mentoring programs should try to match mentees and mentors as much as possible, carefully train and caution mentors with regard to establishing appropriate professional relationships with mentees and do professional development with mentees as well as mentors before the program begins. (Published By University of Alabama Libraries