998 resultados para Speech Synthesis
Resumo:
Under current academic calendars across North America, summer vacation creates a significant gap in the learning cycle. I t has been argued that this gap actually decreases student achievement levels over the course of the summer. In a synthesis of 39 studies Cooper, Nye, Charlton, Lindsay, & Greathouse (1996) indicated that summer learning loss equaled at least one month of instruction as measured by grade level equivalents on standardized test scores whereby children's test scores were at least one month lower when they returned to school in the fall than scores were when students left in the summer. Specifically, Cooper et aI., (1996) found that the summer learning loss phenomena may be particularly troublesome for less advantaged children including those with speech and language delays, children at-risk for reading disabilities, children from lower socio-economic backgrounds, and children learning English as a second language. In general, research illustrated clearly that the summer learning gap can be particularly problematic for vulnerable children and furthermore, that literacy skills may be the area of achievement that is most affected. A foundational pillar to this research project is including primary caregivers as authentic partners in a summer literacy program designed to support their children's literacy needs. This pillar led the research team to use the Learning Begins at Home: A Research-Based Family Literacy Program Curriculum designed by Antoinette Doyle, Kathleen Hipfner-Boucher, and Janette Pelletier from the Ontario Institute for the Studies of Education. The LBH program is designed to be flexibly adapted to suit the needs of each individual participating family. As indicated by Timmons (2008) literacy interventions are most powerful when they include authentic family involvement. Based on this research, a requirement for participating in the summer literacy program was involvement of a child and one of their primary caregivers. The participating caregiver was integrally involved in the program, participating in workshop activities prior to and following hands-on literacy work with their child. By including primary caregivers as authentic partners, the research team encouraged a paradigmatic shift in the family whereby literacy activities become routine within their household. 5 Participants in this study were 14 children from junior kindergarten classrooms within the Niagara Catholic District School Board. As children were referred to the program, they were assessed by a trained emergent literacy specialist (from Speech Services Niagara) to identify whether they met the eligibility requirements for participation in the summer program. To be eligible to participate, children demonstrated significant literacy needs (i.e. below 25%ile on the Test of Preschool Early Literacy described below). Children with low incidence disabilities (i.e. profound sensory impairments, severe intellectual impairments, developmental disabilities, etc) were excluded as participants. The research team used a standard pre- and posttest design whereby all participating children were assessed with the Test of Preschool Early Literacy (Lonigan et aI., 2007), and a standard measure of letter names and sounds. Pretests were administered two weeks prior to the commencement of the program and the first set of posttests was administered immediately following the program. A second set of posttests was administered in December 2009 to measure the sustainability of the program. As a result of the program, all children scored statistically significantly higher on their literacy scores at the post-program assessment point immediately following the program and also at the Dec-post-program assessment point. These results in general indicated that the summer family literacy program made an immediate impact on the emergent literacy skills of participating children. All participating children demonstrated significant increases in print and phonological awareness as well as their letter sound understanding.
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(A) Solid phase synthesis of oligonucleotides are well documented and are extensively studied as the demands continue to rise with the development of antisense, anti-gene, RNA interference, and aptamers. Although synthesis of RNA sequences faces many challenges, most notably the choice of the 2' -hydroxy protecting group, modified 2' -O-Cpep protected ribonucleotides were synthesized as alternitive building blocks. Altering phosphitylation procedures to incorporate 3' -N,N-diethyl phosphoramidites enhanced the overall reactivity, thus, increased the coupling efficiency without loss of integrety. Furthermore, technical optimizations of solid phase synthesis cycles were carried out to allow for successful synthesis of a homo UIO sequences with a stepwise coupling efficiency reaching 99% and a final yield of 91 %. (B) Over the past few decades, dipyrrometheneboron difluoride (BODIPY) has gained recognition as one of the most versatile fluorophores. Currently, BODIPY labeling of oligonucleotides are carried out post-synthetically and to date, there lacks a method that allows for direct incorporation of BODIPY into oligonucleotides during solid phase synthesis. Therefore, synthesis of BODIPY derived phosphoramidites will provide an alternative method in obtaining fluorescently labelled oligonucleotides. A method for the synthesis and incorporation of the BODIPY analogues into oligonucleotides by phosphoramidite chemistry-based solid phase DNA synthesis is reported here. Using this approach, BODIPY-labeled TlO homopolymer and ISIS 5132 were successfully synthesized.
Resumo:
This thesis explored the development of several methodologies for the stereoselective construction of ligand frameworks and some of their applications. The first segment concerns the application of an enantioselective lithiation at an Sp3_ hybridized position adjacent to nitrogen by means of the widely used and typically highly effective enantioselective lithiation with ( -)-sparteine. This investigation was intended to develop a method to install chirality into a system that would be converted into a family of diaminoylidenes for use as phosphine mimics in transition metal catalysis or as nucleophilic reagents. Molecular modeling of the system revealed some key interactions between the substrate and (-)-sparteine that provided general insight into the diamine's mode of action and should lend some predictive value to its future applications. The second portion focuses on the development of methods to access 1,2- disubstituted aminoferrocenes, an underexplored class of metallocenes possessing planar chirality. Two routes were examined involving a diastereoselective and an enantioselective pathway, where the latter method made use of the first BF3-mediated lithiation-substitution to install planar chirality. Key derivatives such as 1,2- aminophosphines, made readily accessible by the new route, were evaluated as ligands for Pd(II), Pt(II) and Ir(I). These complexes show activity in a number of transformations with both achiral and prochiral substrates. Optimization experiments were conducted to prepare enantiomerically enriched 2-substituted-I-aminoferrocenes by direct asymmetric lithiation of BF3-coordinated tertiary aminoferrocenes. A predictive computational model describing the transition state of this reaction was developed in collaboration with Professor Travis Dudding's group (Department of Chemistry, Brock University). The predicted stereochemistry of the process was confirmed by single-crystal X-ray analysis of a 2-phosphino-l-dimethylaminoferrocene derivative. Enantiomerically pure samples of the aminophosphine ligands derived from this new process have given promising preliminary results in the enantioselective hydrogenation of prochiral alkenes and warrant further stUdy in metal-mediated catalysis.
Resumo:
The present studies describe our recent work on expanding the use of the Burgess reagent and its reaction with oxiranes. Several new variants of the Burgess reagent and its chiral auxiliary version were evaluated for their thermal stability by NMR spectroscopy. Three new versions of the reagent were synthesized and their stability was determined. The reactivity of all five Burgess reagents was compared in a dehydration reaction and reactions with epoxides and diols. Progress toward a chemoenzymatic synthesis of morphine is also included in this report. The synthesis began with the whole cell oxidation of bromobenzene by Escherichia coli JMI09(pDTG601). The preparation of several precursors for a key step involving the lohnson-Claisen rearrangement and progress toward the total synthesis are described.
Resumo:
Printed by Pool and Palfray
Resumo:
Dated at beginning of text : Washington, May 12, 1812. Speech given in the House of Representatives of the United States.