Electrospun, non-woven, fibers have high surface area compared to conventional cast films. The thesis reports on the modification of electrospun fibers to concentrate and/or detect biohazards. In one study, electrospun fibers with affinity for the lectins ricin/concanavalin A were fabricated using molecular imprinting or through binding to immobilized antibodies, aptamers or lectin specific sugars. Attempts to fabricate imprinted electrospun fibers through inclusion of the template during the spinning process proved unsuccessful. However, electrospun fibers with affinity towards biohazards were successfully produced by post-modification with antibodies, aptamers or lectin specific saccharides. With regards to the latter, dextran, mannose and chitosan were immobilized onto nylon electrospun fibers that were partially hydrolyzed or treated with cyanuric chloride. The sugar-modified fibers bound significantly higher amount of lectins. Electrospun fibers were also fabricated, post modified with antibodies to capture and detect Salmonella. The study has illustrated the utility of electrospun fibers for biohazard diagnostics. / The National Center for Food Protection and Defense. USA

Genomic imprinting is a phenomenon through which a subset of genes are epigenetically marked during gemtogenisis. This mark is maintained in the soma to often manifest parent of origin-specific monoalleleic expresson patterns. Genetics evidence suggests that gene expression patterns in mprinted genes, which are frequently organised in clusters, are regulated by the imprinting control regions (ICR). This thesis is mainly focused on the mechanisms through which the ICRs control the imprinting in the cluster, containing the Kcnq1, Igf2 and H19 genes, located at the distal end of mouse chromosome 7. The H19 ICR, located in the 5' flank of the H19 gene represses paternal H19 and maternal Igf2 expression, respectively, but has no effect on Kcnq1 expression, which is controlled by another ICR located at the intron 10 of the Kcnq1 gene. This thesis demonstrates that the maternal H19 ICR allele contains several DNase I hypersensitive sites, which map to target sites for the chromatin insulator protein CTCF at the linker regions between the positioned nucleosomes. The thesis demonstrates that the H19 ICR acts as a unidirectional insulator and that this property invovles three nucleosome positioning sites facilitating interaction between the H19 ICR and CTCF. The Kcnq1 ICR function is much more complex, since it horbours both lineage-specific silencing functions and a methylation sensitive unidirectional chromatin insulator function. Importantly, the thesis demonstrates that the Kcnq1 ICR spreads DNA methylation into flanking region only when it is itself unmethylated. Both the methylation spreading and silencing functions map to the same regions. In conclusion, the thesis has unraveled and unrivalled complexity of the epigenetic control and function of short strtches of sequences. The epigenetic status of these cis elements conspires to control long-range silencing and insulation. The manner these imprinting control regions can cause havoc in expresson domains in human diseases is hence emerging.

Epigenetic differences between maternally inherited and paternally inherited chromosomes, such as CpG methylation, render the maternal and paternal genome functionally inequivalent, a phenomenon called genomic imprinting. This functional inequivalence is exemplified with imprinted genes, whose expression is parent-of-origin specific. The dosage of imprinted gene expression is disrupted in cells with uniparental disomy (UPD), which is an unequal parental contribution to the genome. I have derived mouse embryonic stem (ES) cell sub-lines with maternal UPD (mUPD) for mouse chromosome 6 (MMU6) to characterize regulation and maintenance of imprinted gene expression. The main finding from this study is that maintenance of imprinting in mitotic UPD is extremely variable. Imprint maintenance was shown to vary from gene to gene, and to vary between ES cell lines depending on the mechanism of loss of heterozygosity (LOH) in that cell line. Certain genes analyzed, such as Peg10, Sgce, Peg1, and Mit1 showed abnormal expression in ES cell lines for which they were mUPD. These abnormal expression levels are similar to that observed in ES cells with meiotically-derived full genome mUPD (parthenogenetic ES cells). Imprinted CpG methylation at the Peg1 promoter was found to be abnormal in all sub-lines with mUPD for Peg1. Two cell sub-lines which incurred LOH through mitotic recombination showed hypermethylation of Peg1, consistent with the presence of two maternal alleles. Surprisingly, a cell sub-line which incurred LOH through full chromosome duplication/loss showed hypomethylation of Peg1. The levels of methylation observed in these sub-lines correlates with expression, as the first two sub-lines showed a near-consistent reduction of Peg1, while the latter showed Peg1 levels close to wild-type. Altogether these results suggest that certain imprinted genes, like Peg1 and Peg10, have stricter imprinting maintenance, and as a result show abnormal expression in UPD. This strict imprint maintenance is disrupted, however, in UPD incurred through full chromosome duplication/loss, possibly because of the trisomic intermediate stage which occurs in this mechanism.

The imprinted expression of the IGF2 and H19 genes is controlled by the imprinting control region 1 (ICR1) located at chromosome 11p15.5. This methylation-sensitive chromatin insulator works by binding the zinc-finger protein CTCF in a parent-specific manner. CTCF binds the unmethylated maternal allele and is required for preventing de novo methylation at ICR1. DNA methylation defects involving the ICR1 IGF2/H19 domain result in two growth disorders with opposite phenotypes: an overgrowth disorder, the Beckwith-Wiedemann syndrome (ICR1 gain of methylation in 10% of BWS cases) and a growth retardation disorder, the Silver-Russell syndrome (ICR1 loss of methylation in 60% of SRS cases). Little information is available regarding the mechanism of ICR1 DNA methylation defects. Several deletions removing part of ICR1 (1.4 to 2.2 kb) have been described in a few familial BWS cases with dominant maternal transmission. In order to evaluate precisely the incidence of ICR1 mutations, we investigated, by long range PCR and sequencing, 21 BWS patients (including two brothers) with ICR1 gain of methylation and 16 SRS patients with ICR1 loss of methylation. No mutation of the seven CTCF binding sites was detected in the familial BWS cases. Two additional cases of constitutional genetic lesions were identified in BWS patients with apparently-sporadic forms. One patient was identified with a 8 bp deletion within the B3 repeat, 116 bases 3' of the CTCF binding site 4. Another patient was identified with a 1.8 kb deletion which eliminates CTCF binding sites 2 and 3. A single-nucleotide variation was identified in a SRS patient. Our data showed that ICR1 deletions, including new small deletions, account for apparently sporadic forms of BWS with ICR1 gain of methylation. ICR1 deletions are associated with a high incidence of Wilms' tumour, making their molecular diagnosis particularly important for genetic counseling and tumor surveillance.

Tez (Doktora) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Kimya Anabilim Dalı, 2008. / Bibliyografya var.

Thesis (Ph.D.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 141 pages. Includes Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 148 pages. Includes Vita. Includes bibliographical references.

O processamento de peles para a fabricação de couro utiliza uma mistura complexa de substâncias - dentre elas, os taninos - que torna o tratamento de águas residuais difícil e oneroso. Vários estudos estão sendo conduzidos na tentativa de melhorar o tratamento e até mesmo reutilizar o efluente tratado. Neste trabalho foi avaliado o desenvolvimento de adsorventes funcionais sintetizados pelo método solgel e dotados de impressão molecular, para adsorção de compostos de taninos. Por serem de fácil preparação, os materiais híbridos obtidos viabilizam a sua produção para o uso como sólidos adsorventes. A caracterização dos materiais híbridos orgânico-inorgânico obtidos foi realizada por análise de Porosimetria de nitrogênio (BET), Espalhamento de raios-X a baixo ângulo (SAXS), Espectroscopia de refletância difusa no UV-vis (DRS), Espectroscopia de infravermelho com transformada de Fourier (FT-IR) e Potencial Zeta (PZ). As características estruturais e texturais dos materiais híbridos gerados variaram para cada rota sol-gel e processo de extração de template empregado, resultando em materiais com diferentes capacidades de adsorção. As sílicas sem funcionalização não foram capazes de adsorver os compostos de tanino em solução aquosa, enquanto que as sílicas funcionalizadas com APTES demonstraram sua potencialidade como adsorvente para os compostos testados, atingindo remoções superiores a 80%. Diferenças nas capacidades de adsorção entre as sílicas funcionalizadas com e sem impressão molecular também foram observadas, onde a sílica sem impressão apresentou uma adsorção superior de taninos, indicando que mais estudos são necessários para encontrar um processo de extração eficiente do template. É importante salientar que as sílicas que obtiveram a maior capacidade de adsorção, puderam adsorver os compostos de taninos por vários ciclos consecutivos. / The processing of hides for leather manufacturing uses a complex mix of chemicals that makes the wastewater treatment difficult and costly. Several studies are being conducted in attempt to improve the treatment and even reuse the treated effluent. This study evaluated the development of functional adsorbent synthesized by the molecular imprinting method in a sol-gel matrix, for adsorbing tannin compounds. Easy to prepare, hybrid materials obtained enable their production for use as solid adsorbents. The characterization of organic-inorganic hybrid materials obtained was performed by nitrogen porosimetry analysis (BET), small-angle X-ray scattering (SAXS), diffuse reflectance spectroscopy (DRS), Fourier-Transform Infrared Spectroscopy (FT-IR) and Zeta Potential (PZ). The structural and textural characteristics of hybrid materials ranged for each sol-gel route and template employed extraction process resulting in materials with different adsorption capacities. The silicas without functionalization were unable to adsorb the tannin compounds in aqueous solution, whereas the silica functionalized with APTES demonstrated the potential of the adsorbent for the tested compounds, with removals above of 80%. Differences in adsorption capacities between functionalized silica with and without molecular imprinting were observed where the unprinted silica had a higher adsorption of tannins, indicating that more studies are needed to find a process of efficient template extraction to improve adsorption capacity to the imprinted materials. Further, the silicas with improved adsorption capacity could adsorb the tannin compounds for several consecutive cycles of adsorption.

Northern bobwhite (hereafter, bobwhite; Colinus virginianus) have experienced long-term declines in population abundance throughout most of their breeding range. In 2004, the United States Department of Agriculture (USDA) authorized mid-contract management (MCM) to restore early successional plant communities in aging Conservation Reserve Program (CRP) fields. I evaluated the effects of 3 MCM regimes, including fall strip disking, fall herbicide spraying (hereafter, spray), and fall herbicide spraying in combination with spring legume interseeding (hereafter, spray-seed) on nearly 650 ha of tall fescue (Schedonorus phoenix [Scop]. Holub; nomenclature follows USDA plants database; see USDA 2010b) CRP in south-central Illinois, USA, during 2005-2008. The objectives of this study were to: 1) evaluate the compositional and structural responses of the vegetation community to MCM, 2) determine the structural vegetation and landscape composition variables that influenced adult bobwhite relative densities and brood presence in CRP, and 3) assess foraging rates and arthropod prey selection of bobwhite chicks relative to MCM. Spray and spray-seed treatments were more effective than disking at reducing tall fescue cover, increasing plant species diversity, and enhancing the structural characteristics of the plant community that are essential for nesting and brood-rearing bobwhite. Spray-seed and disked treatments increased the percentage of bare ground by burying the dead and dying vegetative biomass beneath the soil surface. However, spraying alone left large amounts of litter accumulation on the soil surface that resulted in a delay in the timing of some annual forbs to recolonize. Plant species composition in sprayed and spray-seeded fields changed from a dense, monoculture of tall fescue to a diverse assemblage of perennial grasses, annual forbs, and legumes that provided habitat for nesting and brood-rearing bobwhite. Adult bobwhite and broods responded positively to spray and spray-seed treatments in this study. Adult relative densities (i.e., number of adult bobwhite observed / ha) were higher in sprayed and spray-seeded fields than in disked and controls. The probability of higher relative densities was greater in fields with higher plant species diversity, and percentages of bare ground and legumes. Conversely, relative densities were negatively associated with higher percentages of grass cover. At the landscape scale, relative densities were positively correlated higher percentages of cropland and pastureland within a 250 m buffer of CRP fields. Sprayed and spray-seeded fields were 39.6% more likely to have broods present than control fields. Whereas disked fields were only 10.0% more likely to have broods than controls. Brood presence was positively correlated with higher percentages of bare ground and negatively correlated with higher percentages of grass cover. Human-imprinted bobwhite chicks consumed a higher abundance and biomass of arthropods in sprayed and spray-seeded fields than in disked and controls, although the abundance of arthropods available was generally highest in control and disked fields. This suggests, therefore, that bobwhite chicks foraging rates are not limited by arthropod availability, but rather, by the structure of the vegetative community and the ability of the chicks to access the food resources. Chicks consumed a higher proportion of hymenopterans, isopods, and lepidopterans than expected from nonrandom feeding indicating that they were actively selecting for particular prey. This research has added to the understanding of restoring bobwhite habitat to tall fescue CRP, and could assist USDA-Natural Resource Conservation Service personnel and other land managers in restoring and maintaining marginally diverse grassland ecosystems in CRP fields for nesting and brood-rearing bobwhite.

O processamento de peles para a fabricação de couro utiliza uma mistura complexa de substâncias - dentre elas, os taninos - que torna o tratamento de águas residuais difícil e oneroso. Vários estudos estão sendo conduzidos na tentativa de melhorar o tratamento e até mesmo reutilizar o efluente tratado. Neste trabalho foi avaliado o desenvolvimento de adsorventes funcionais sintetizados pelo método solgel e dotados de impressão molecular, para adsorção de compostos de taninos. Por serem de fácil preparação, os materiais híbridos obtidos viabilizam a sua produção para o uso como sólidos adsorventes. A caracterização dos materiais híbridos orgânico-inorgânico obtidos foi realizada por análise de Porosimetria de nitrogênio (BET), Espalhamento de raios-X a baixo ângulo (SAXS), Espectroscopia de refletância difusa no UV-vis (DRS), Espectroscopia de infravermelho com transformada de Fourier (FT-IR) e Potencial Zeta (PZ). As características estruturais e texturais dos materiais híbridos gerados variaram para cada rota sol-gel e processo de extração de template empregado, resultando em materiais com diferentes capacidades de adsorção. As sílicas sem funcionalização não foram capazes de adsorver os compostos de tanino em solução aquosa, enquanto que as sílicas funcionalizadas com APTES demonstraram sua potencialidade como adsorvente para os compostos testados, atingindo remoções superiores a 80%. Diferenças nas capacidades de adsorção entre as sílicas funcionalizadas com e sem impressão molecular também foram observadas, onde a sílica sem impressão apresentou uma adsorção superior de taninos, indicando que mais estudos são necessários para encontrar um processo de extração eficiente do template. É importante salientar que as sílicas que obtiveram a maior capacidade de adsorção, puderam adsorver os compostos de taninos por vários ciclos consecutivos. / The processing of hides for leather manufacturing uses a complex mix of chemicals that makes the wastewater treatment difficult and costly. Several studies are being conducted in attempt to improve the treatment and even reuse the treated effluent. This study evaluated the development of functional adsorbent synthesized by the molecular imprinting method in a sol-gel matrix, for adsorbing tannin compounds. Easy to prepare, hybrid materials obtained enable their production for use as solid adsorbents. The characterization of organic-inorganic hybrid materials obtained was performed by nitrogen porosimetry analysis (BET), small-angle X-ray scattering (SAXS), diffuse reflectance spectroscopy (DRS), Fourier-Transform Infrared Spectroscopy (FT-IR) and Zeta Potential (PZ). The structural and textural characteristics of hybrid materials ranged for each sol-gel route and template employed extraction process resulting in materials with different adsorption capacities. The silicas without functionalization were unable to adsorb the tannin compounds in aqueous solution, whereas the silica functionalized with APTES demonstrated the potential of the adsorbent for the tested compounds, with removals above of 80%. Differences in adsorption capacities between functionalized silica with and without molecular imprinting were observed where the unprinted silica had a higher adsorption of tannins, indicating that more studies are needed to find a process of efficient template extraction to improve adsorption capacity to the imprinted materials. Further, the silicas with improved adsorption capacity could adsorb the tannin compounds for several consecutive cycles of adsorption.