Many microwave (RF) circuit designs require passive distributed sub-components with prescribed scattering parameters. These sub-components have typically been realised by cascading building-block configurations (eg. transmission lines of specific lengths, bends in transmission lines, coupled lines, and so on) of standard shape, and then adjusting the dimensions of selected prescribed features of these building-blocks. The problem with this approach is that the resulting sub-component may take up more "real-estate" on the overall circuit board than can be tolerated, may require tolerances that are too tight and hence be more costly than product developers can allow, can lead to less-than-best performance because we select the building-blocks (that we think are needed) ahead of time, and so on. The research in this thesis contributes to the shape synthesis approach of physical microstrip circuit design. The shape synthesis process is usually contrasted to traditional design by recognizing that it does not merely adjust the dimensions of a set of prescribed geometrical features on pre-selected shapes, but allows the electromagnetic physics to tell us what the sub-component layout needs to be (and it can be unconventional) in order to obtain the required performance. Existing shape synthesis techniques are based on the discrete- or continuous-pixelation method. Each of these approaches, however, have disadvantages (eg. too many degrees of freedom required to achieve the geometrical resolution necessary; the need for arbitrary decisions to fix material properties) that have prevented shape synthesis from being accepted for widespread use in design practice. In this thesis we develop, implement and apply a completely new shape synthesis approach, called the subtractive approach, that overcomes many of the above-mentioned disadvantages of pixelation-based methods It reduces the number of variables (degrees of freedom) needed in spite of the fact that the "design space" is significantly broadened by this approach. The latter is confirmed by the fact that it produces physical circuit geometries that we would not have come up with using traditional design methods. Examples are provided of the application of the new subtractive shape synthesis method. This new method involves continuous variables directly related to the physical circuit geometry, and thus could be used with surrogate modelling, unlike some existing shape synthesis procedures.

Water stress affects vine productivity, disease tolerance, and enological characteristics of grape. Florida Hybrid Bunch grape are developed through hybridization of local grape spp with Vitis vinifera. These cultivars are mostly grown in southeast region of United States. Water deficit conditions resulted due to failure of rains in the region has developed concern among Florida grape growers to increase water use efficiency of grape. The goal of this research is to identify genes and proteins differentially expressed in response to water stress and to correlate these changes with enological characteristics. Investigating transcripts and proteins will allow us to correlate them and confirm the involvement of specific genes responding to stress. Florida hybrid bunch ‘Suwannee’ grape plants were maintained under green house conditions. Water stress was induced by withholding irrigation. The leaf samples were collected from both irrigated and stressed plants at 5, 10, 15 and 20 day interval. We generated over 200 Subtractive Hybridization PCR products from control and water stressed leaf tissues. Cloning, sequencing and transcript analysis revealed that, 54 genes related to drought and defense regulated pathways out of 125 characterized transcripts. Proteins were extracted from leaf tissue with trichloroacetic acid /acetone and separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). The proteins were sequenced in LC/Mass Spectrophotometer. The most important differentially expressed genes include sucrose synthase, actin, isoprene synthase, ABF3, SNF1 related protein kinase, WRKY type transcription factors, AP2, ASR2, glyoxalase I and, cytochrome b which play significant role in cell permeability, transportation, photosynthesis and, maintenance in osmotic stress. We have found that ribulose bisphosphate carboxylase and phosphoribulokinase, which play major role in photosynthesis, were suppressed in response to water stress in Florida hybrid bunch. The results suggested that water stress affects expression of cDNAs associated with defense and drought regulated functions. Such profiling studies will be used to explicate specific pathways disconcerted by water deficit treatments, and in the identification of varietal differences.

Paracoccidioides brasiliensis, um fungo termodimórfico, é o agente causador da paracoccidioidomicose (PCM), a micose sistêmica prevalente da América Latina. A patogenicidade aparenta estar intimamente relacionada com a transição dimórfica da forma de micélio para a de levedura, que é induzida pela mudança da temperatura do ambiente pela temperatura do hospedeiro mamífero. Há poucas informações disponíveis sobre genes de P. brasiliensis que são necessários durante a fase patogênica. Nós, então, realizamos as técnicas de SSH (“Suppression Subtraction Hybridization") e de “Macroarray" com o objetivo de identificar genes que sejam preferencialmente expressos na fase leveduriforme do isolado Pb18. Genes identificados em ambos os procedimentos estão mais expressos na fase leveduriforme e estão envolvidos em metabolismo básico, transdução de sinal, crescimento e morfogênese e metabolismo do enxofre. Para testar se as mudanças observadas na expressão gênica refletem as diferenças entre as condições de crescimento usadas para obter as duas formas morfológicas preferivelmente às diferenças intrínsecas dos tipos celulares, nós realizamos experimentos com RT-PCR em tempo real utilizando preparações de RNA derivadas de ambas as fases, micélio e levedura, crescidas a 26°C e 37°C nos meios de cultura completos (YPD e Sabouraud) e meio mínimo. Vinte genes, incluindo AGS1 ( -1,3-glucan synthase) e TSA1 (thiol-specific antioxidant), foram mostrados como mais expressos na levedura patogênica em relação ao micélio. Embora a expressão de RNA mensageiro foi bastante diferente em relação aos meios completos e meio mínimo, mostramos uma tendência geral para que esses genes serem mais expressos nas células leveduriformes patogênicas de P.x brasiliensis. Além disso, mostramos a complementação dos genes METR e SCONC de P. brasiliensis e uma cepa com estes genes deletados de Aspergillus nidulans, sugerindo uma possível homologia entre eles. Mostramos também a análise de genes da via do metabolismo do enxofre foram mais expressos na levedura patogênica de P. brasiliensis em relação ao micélio saprofítico. / Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of paracoccidioidomycosis (PCM), a prevalent systemic mycosis in Latin America. Pathogenicity appears to be intimately related to the dimorphic transition from the hyphal to the yeast form, which is induced by a shift from environmental temperature to the temperature of the mammalian host. Little information is available on the P. brasiliensis genes necessary during the pathogenic phase. We have therefore undertaken Suppression Subtraction Hybridization (SSH) and macroarray analyses with the aim of identifying genes that are preferentially expressed in the yeast phase. Genes identified by both procedures as being more highly expressed in the yeast phase are involved in basic metabolism, signal transduction, growth and morphogenesis, and sulfur metabolism. In order to test whether the observed changes in gene expression reflect the differences between the growth conditions used to obtain the two morphological forms rather than differences intrinsic to the cell types, we performed real-time RT-PCR experiments using RNA derived from both yeast cells and mycelia that had been cultured at 37 and 26°C in either complete medium (YPD or Sabouraud) or minimal medium. Twenty genes, including AGS1 ( 1,3-glucan synthase) and TSA1 (thiol-specific antioxidant), were shown to be more highly expressed in the yeast cells than in the hyphae. Although their levels of expression could be different in rich and minimal media, there was a general tendency for these genes to be more highly expressed in the yeast cells. Moreover, complementation of P. brasiliensis METR and SCONC genes in strains of Aspergillus nidulans with these genes deleted suggested a possible homology between them. We show the analyses of genes involved in the xii sulphur metabolism pathway and these genes were more expressed in the pathogenic yeast than saprophytic mycelia of P. brasiliensis.

Paracoccidioides brasiliensis, um fungo termodimórfico, é o agente causador da paracoccidioidomicose (PCM), a micose sistêmica prevalente da América Latina. A patogenicidade aparenta estar intimamente relacionada com a transição dimórfica da forma de micélio para a de levedura, que é induzida pela mudança da temperatura do ambiente pela temperatura do hospedeiro mamífero. Há poucas informações disponíveis sobre genes de P. brasiliensis que são necessários durante a fase patogênica. Nós, então, realizamos as técnicas de SSH (“Suppression Subtraction Hybridization”) e de “Macroarray” com o objetivo de identificar genes que sejam preferencialmente expressos na fase leveduriforme do isolado Pb18. Genes identificados em ambos os procedimentos estão mais expressos na fase leveduriforme e estão envolvidos em metabolismo básico, transdução de sinal, crescimento e morfogênese e metabolismo do enxofre. Para testar se as mudanças observadas na expressão gênica refletem as diferenças entre as condições de crescimento usadas para obter as duas formas morfológicas preferivelmente às diferenças intrínsecas dos tipos celulares, nós realizamos experimentos com RT-PCR em tempo real utilizando preparações de RNA derivadas de ambas as fases, micélio e levedura, crescidas a 26°C e 37°C nos meios de cultura completos (YPD e Sabouraud) e meio mínimo. Vinte genes, incluindo AGS1 ( -1,3-glucan synthase) e TSA1 (thiol-specific antioxidant), foram mostrados como mais expressos na levedura patogênica em relação ao micélio. Embora a expressão de RNA mensageiro foi bastante diferente em relação aos meios completos e meio mínimo, mostramos uma tendência geral para que esses genes serem mais expressos nas células leveduriformes patogênicas de P.x brasiliensis. Além disso, mostramos a complementação dos genes METR e SCONC de P. brasiliensis e uma cepa com estes genes deletados de Aspergillus nidulans, sugerindo uma possível homologia entre eles. Mostramos também a análise de genes da via do metabolismo do enxofre foram mais expressos na levedura patogênica de P. brasiliensis em relação ao micélio saprofítico. / Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of paracoccidioidomycosis (PCM), a prevalent systemic mycosis in Latin America. Pathogenicity appears to be intimately related to the dimorphic transition from the hyphal to the yeast form, which is induced by a shift from environmental temperature to the temperature of the mammalian host. Little information is available on the P. brasiliensis genes necessary during the pathogenic phase. We have therefore undertaken Suppression Subtraction Hybridization (SSH) and macroarray analyses with the aim of identifying genes that are preferentially expressed in the yeast phase. Genes identified by both procedures as being more highly expressed in the yeast phase are involved in basic metabolism, signal transduction, growth and morphogenesis, and sulfur metabolism. In order to test whether the observed changes in gene expression reflect the differences between the growth conditions used to obtain the two morphological forms rather than differences intrinsic to the cell types, we performed real-time RT-PCR experiments using RNA derived from both yeast cells and mycelia that had been cultured at 37 and 26°C in either complete medium (YPD or Sabouraud) or minimal medium. Twenty genes, including AGS1 ( 1,3-glucan synthase) and TSA1 (thiol-specific antioxidant), were shown to be more highly expressed in the yeast cells than in the hyphae. Although their levels of expression could be different in rich and minimal media, there was a general tendency for these genes to be more highly expressed in the yeast cells. Moreover, complementation of P. brasiliensis METR and SCONC genes in strains of Aspergillus nidulans with these genes deleted suggested a possible homology between them. We show the analyses of genes involved in the xii sulphur metabolism pathway and these genes were more expressed in the pathogenic yeast than saprophytic mycelia of P. brasiliensis.

The objective of this study was to identify genes that are differentially regulated during diapause when compared with nondiapausing pupae in Sarcophaga crassipalpis. The results of a Suppression Subtractive Hybridization procedure was used to indentify genes that are differentially regulated in both diapause and nondiapausing states while suppressing genes that are common to both states. Randomly picked colonies from both subtractive libraries were isolated and the inserts sequenced. The sequences were analyzed using the bioinformatics tools NCBI, BlastX, Clustal W, etc. Out of 384 clones, 59 genes were found to be upregulated during diapause and 37 genes were found to be upregulated during a nondiapause pupal stage, no genes were found to be expressed commonly in both the diapause and nondiapause constructed libraries.

Objective: The purpose of this study was to evaluate the accuracy of surgical guides for dental implant placement fabricated by additive and subtractive techniques. Methods: A standardized mandible model (BoneModels, Castellón, Spain) was duplicated and the proposed implant position was performed from a diagnostic wax-up. An implant was placed in the printed model as a reference. Cone beam computed tomography (CBCT) was made with the radiographic surgical guide to design a surgical guide on BlueSky Plan 4 software. The .stl file of the surgical guide was exported and fabricated by two different techniques: additive (3D printing) and subtractive (milling). Fifteen surgical guides per group were used to place implants in the printed models. The angular deviations, differences in depth, coronal and apical deviations were measured using GeoMagic Control X software. Results were analyzed by Wilcoxon-Mann-Whitney (Wilcoxon Rank Sum) test and PERMANOVA (Permutational Multivariate Analysis of Variance). Intraclass correlation was used to analyze the reproducibility. A 0.05 level of significance was used, with Bonferroni multiple adjustment as needed. Results: There were no significant differences in accuracy of implant placement using additive technique vs subtractive techniques. The mean angular deviations between planned and actual position of implant in mesio-distal cross-section were 0.780±0.803 degrees for printed group and 0.772±0.724 degrees for the milled group. The analogous results in bucco-lingual cross-section were 1.601±1.223 degrees in in printed group and 1.767±0.762 degrees in the milled group. The differences in depth (mm) were measured in four aspects including mesial, distal, buccal and lingual. The mean differences in depth in the group that using printed surgical guides were 0.373±0.285 mm, 0.325±0.230 mm, 0.240±0.228 mm, and 0.247±0.168 mm in those 4 aspects, respectively. The mean differences in depth in the group that using milled surgical guides were 0.511±0.326 mm, 0.396±0.316 mm, 0.215±0.230 mm, and 0.230±0.122 mm in those four aspects, respectively. The mean coronal deviation showed 0.32 mm in the printed group and 0.27 mm in the milled group. For the apical deviation, the results of this study showed mean apical deviation 0.84 mm in the printed group and 0.80 mm in the milled group. Conclusions: No statistically significant difference was identified between the position of implant placed using surgical guide fabricated by the additive technique (3D printing) vs surgical guides fabricated by subtractive technique (milling). The 3D-printed surgical guide could be an alternative for guided-implant surgery with the benefits of high accuracy, ease of fabrication and reduction of laboratory time and materials, thereby increasing cost-effectiveness.

Latino students are at risk for poor social and academic outcomes in American schools, yet contextual models for understanding this risk have been elusive. Considerable research has attempted to understand the relation between the ethnic composition of schools and outcomes for Latino students, with inconsistent findings. It was hypothesized that school ethnic composition would be differentially related to outcomes in this population of students, depending on other school contextual factors. Using secondary data from the National Longitudinal Study of Adolescent Health (Add Health), the present study examined individual and school-level moderators of the slopes of same-ethnicity representation (i.e., the percentage of same-ethnicity peers) and ethnic diversity predicting feelings of school belonging and the odds of high school completion among Latino youths. The results illustrate moderation of the slopes of ethnic composition variable depending on the socioeconomic status (SES) of schools as well as the extent of academic tracking. In low SES schools, same-ethnicity representation was positively related to both outcomes (belonging and completion) when academic tracking was low. In high SES schools, the slope of same-ethnicity representation predicting the odds of high school completion was negative under conditions of low ethnic diversity. Diversity was itself positively associated with high school completion across contexts, yet this relation was moderated by SES at the student level. Specifically, the association between diversity and completion diminished as student SES decreased, relative to the mean SES of students in a school. Altogether, the results suggest that conditions associated with reduced inequality among students, namely low systemic strain (higher SES) and low academic tracking, are related to more positive associations between both same-ethnicity representation and diversity, and social and academic outcomes for Latino students. Future research is advised to consider the intersection of school ethnic composition with other aspects of the school context as well as with characteristics of individual students.

The present study investigated the possibility of heritage language loss in twenty students of Hispanic origin, selected from six second-grade classrooms in one elementary school of a large district in the Dallas-Fort Worth area. Ten students were enrolled in Transitional Bilingual Education (TBE) classes and ten students were enrolled in English as a Second Language (ESL) classes, during the academic year 2004-2005. Oral Reading Fluency (ORF) in English and Spanish were measured over a short-term progress monitoring period (i.e. sixteen consecutive weeks), and over a long-term follow-up period (i.e. nine and twelve months later, respectively). To answer the first research question on the amount and type of growth in English and Spanish ORF demonstrated by the students over time, two main types of analyses were conducted: a) time series analysis of group improvement trends, and b) Analysis of Variance (ANOVA) on individual student slope coefficients. Results from quantitative analyses revealed that both groups of students improved in English reading over time. However, when considering the long-term progress, the TBE group demonstrated a faster rate of improvement in English reading when compared to the ESL group and also to their own Spanish reading. As for the ESL group, the students reached a plateau of performance in Spanish, indicating, at best, minimal skills in the heritage language while continuing to progress in English. To answer the second research question, regarding parents’ beliefs on bilingualism and maintenance of the heritage language in their children, semistructured Parents’ Interviews (PI) with open-ended questions were conducted. Results from qualitative analyses revealed three major themes: Both sets of parents believed in the connection between the native language and increased life opportunities, the TBE parents affirmed the heritage language as symbol of their cultural identity, and the ESL parents acknowledged their children’s native language loss. Findings from this study suggest that students instructed in their native language in the early elementary years appear to have a better chance of maintaining their heritage language over time, when compared to students instructed solely in English.

Yellow rust disease is one of the most important problems in wheat production. It causes substantial yield losses throughout the world. There are resistant and susceptible wheat varieties to various yellow rust pathotypes. In this thesis genes that are induced in wheat, in virulence and avirulence conditions upon yellow rust inoculations were investigated. Consequently, it was aimed to identify genes that may be playing critical roles in the disease resistance mechanism. The strategy was to construct subtracted cDNA libraries from resistant and susceptible plants and analyse the sequences obtained from these libraries. The subtraction approach in this study differs from the common subtraction designs implicated in plant-pathogen interactions / instead of comparing a compatible or an incompatible interaction with a control, one of the subtractions in this study is done taking a compatible interaction as the tester and an incompatible one as the driver, and the second subtraction, vice versa. Therefore, it was intended to compare the transcriptomes from compatible and incompatible plant-pathogen interactions directly. Suppression Subtractive Hybridization method was used to construct subtracted cDNA libraries. Two subtractions were performed / SSH1 (D-R), taking a compatible interaction as the tester sample and an incompatible one as the driver sample, and SSH2 (R-D), taking an incompatible interaction as the tester sample and a compatible one as the driver. In the end, two subtracted cDNA libraries, SSH1 (D-R) library (1536 clones) and SSH2 (R-D) library (1152 clones) were obtained and the libraries were sequenced. Sequence results were subjected to BlastN and BlastX analysis. We looked for a group of genes that were frequently emphasized in plant disease related studies when we searched within the Blast N homology results of the two libraries. We found out that 19 such genes are present in our libraries. We discussed supposed induction of these genes in the interactions investigated in our study. The fact that these genes were found to be present in our libraries enhances the reliability of our results suggesting that the gene sequences we found indeed belong to genes differentially expressed in the respective comparisons investigated in our study. As such, it also implies that other sequences that were found similar to genes of known functions may represent candidate genes as subjects of further studies investigating wheat-yellow rust interactions.

Potato production in tropical and subtropical countries suffers from damage caused by the potato tuber moth (PTM), Phthorimiaea operculella. Development of a germline transformation system and the identification of genes that are differentially expressed within the PTM midgut are the main goals of this research. We tested three components that are critical to genetic transformation systems for insects; promoter activity, marker gene expression, and transposable element function. We compared the transcriptional activities of five different promoters, hsp70, hsp82, actin5C, polyubiquitin and ie1, within PTM embryos. The ie1 promoter flanked with the enhancer element, hr5, showed a very high level of transcriptional activity compared with the other promoters. The expression of the enhanced green fluorescent protein (EGFP) was detected under UV-illumination within the embryonic soma demonstrating that it can be used as an effective marker gene for PTM. The transpositional activities of the Hermes, mariner and piggyBac transposable elements were tested in interplasmid transposition assays. The piggyBac element was shown mobile within the embryonic soma with a transposition frequency of 4.2 X 10-5 transposition/donor plasmid. The piggyBac mobility has been enhanced by incorporating a transactivator plasmid expressing the IE1 protein from the bacoluvirus Autographa californica nuclear polyhedrosis virus. Seven transformation experiments were performed. The experiments failed to produce a transgenic PTM. The insect midgut is a rich region of molecular targets involved in food processing that could be potentially used to design a new control strategy. The suppression subtractive hybridization (SSH) method was used to identify differentially expressed genes from the PTM midgut. From this subtracted library, 2984 clones were collected and screened. Of these clones, 637 clones are candidate differentially expressed genes within the PTM midgut. Sixty-nine cDNA clones were randomly selected for DNA sequencing. Tweleve clones were selected for further analysis using RT-PCR and Northern blot techniques. Eleven of the clones resulted in positive results for midgut expression. Five clones, showing homology with insect immune peptides, were used in the challenge experiment which revealed that these cDNAs are constitutively expressed in the midgut, as well as being up-regulated due to bacterial or viral challenge.