A comparative study compiled from a survey taken in Middleton, Rhode Island concerning educational experiences for preschool children in the home,

Thesis (M.A.)--Boston Universit

The political economy of the Maoist conflict in India : an empirical analysis

This paper contributes to a burgeoning literature that uses sub-national micro data to identify the causes of civil conflicts. In particular, we study the Maoist/Naxalite conflict in India by constructing a comprehensive district level database using conflict data from four different terrorism databases and combining it with socioeconomic and geography data from myriad sources. In addition to exploiting the within country regional heterogeneity, we use the micro structure of the data to construct group-level characteristics. Using data on 360 districts for 3 time periods, we find evidence on how land inequality and lower incomes are important for the Maoist conflict. Moreover, making use of the micro structure of the data we are able to ask whether exclusion of the low castes and tribes from the growth story of India is important. We find that while the income levels of the different ethnic groups are not important, the growth of incomes of Scheduled Tribes significantly decreases the intensity of the conflict. Finally, we show how historical property rights institutions from colonial times that go back centuries can affect present day conflict outcomes through their impact on economic outcomes, social relations and the political environment in the distric

The Biocatalytic Potential of Extremophiles and Extremozymes

Extremophiles are bizarre microorganisms that can grow and thrive in extreme environments, which were formerly considered too hostile to support life. The extreme conditions may be high or low temperature, high or low pH, high salinity, high metal concentrations, very low nutrient content, very low water activity, high radiation, high pressure and low oxygen tension. Some extremophiles are subject to multiple stress conditions. Extremophiles are structurally adapted at the molecular level to withstand these harsh conditions. The biocatalysts, called extremozymes, produced by these microorganisms, are proteins that function under extreme conditions. Due to their extreme stability, extremozymes offer new opportunities for biocatalysis and biotransformation. Examples of extremozymes include cellulases, amylases, xylanases, proteases, pectinases, keratinases, lipases, esterases, catalases, peroxidases and phytases, which have great potential for application in various biotechnological processes. Currently, only 1–2 % of the microorganisms on the Earth have been commercially exploited and amongst these there are only a few examples of extremophiles. However, the renewed interest that is currently emerging as a result of new developments in the cultivation and production of extremophiles and success in the cloning and expression of their genes in mesophilic hosts will increase the biocatalytic applications of extremozymes

Evaluating Student Preparedness and Conceptual Change in Introductory Biology Students Studying Gene Expression

Conceptual difficulties experienced by introductory college biology students studying gene expression are explored in this empirical study. We used an open-ended assessment instrument and a pre-test/post-test design to measure prior knowledge and conceptual change over the course of one semester. Our findings suggest that introductory biology students struggle with the basic terminology necessary to understand complex biological systems at the molecular and genetic level. While conceptual growth from the beginning to the end of the semester was less than expected, learning gains were significant for all concepts examined by our assessment strategy. Qualitative evaluation of pre- and post-tests further highlighted the difficulty students have articulating their knowledge using scientific language. In our discussion, we emphasize the importance of assessing conceptual understanding, developing instructional strategies to promote conceptual change, and the need for closer alignment of curriculum between and within institutions. Ultimately, educational and institutional resources to support faculty development in the area of teaching and learning are critical for the retention and preparation of a diverse student population in the biological sciences

Experimental demonstration of digital predistortion for orthogonal frequency-division multiplexing-radio over fibre links near laser resonance

Radio over fibre (RoF), an enabling technology for distribution of wireless broadband service signals through analogue optical links, suffers from non-linear distortion. Digital predistortion has been demonstrated as an effective approach to overcome the RoF non-linearity. However, questions remain as to how the approach performs close to laser resonance, a region of significant dynamic non-linearity, and how resilient the approach is to changes in input signal and link operating conditions. In this work, the performance of a digital predistortion approach is studied for directly modulated orthogonal frequency-division multiplexing RoF links operating from 2.47 to 3.7 GHz. It extends previous works to higher frequencies, and to higher quadrature amplitude modulation (QAM) levels. In addition, the resilience of the predistortion approach to changes in modulation level of QAM schemes, and average power levels are investigated, and a novel predistortion training approach is proposed and demonstrated. Both memoryless and memory polynomial predistorter models, and a simple off-line least-squares-based identification method, are used, with excellent performance improvements demonstrated up to 3.0 GHz