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Biomimetics is defined as an approach in which naturally occurring materials processes are mimicked in laboratory situations. The ultimate goal is to develop synthetic analogues of naturally occurring materials such as bone and teeth, classified as biocomposites, which possess similar chemical and mechanical properties. The work presented here provides the initial work in furthering the progress of biomimetic materials processing.The first element of the work utilizes molecular imprinting as a selective recognition, or sensing tool, for detection of low molecular weight organic molecules. Molecular imprinting is a phenomenon in which crosslinked synthetic polymers exhibit selective binding towards small organic molecules. Initial work in the field was done in which numerous processing steps were involved with bulk polymer samples while the achievement here lies in the development of molecular imprinted polymer films which greatly facilitate the processing and characterization. Molecularly imprinted polymers are sometimes referred to as artificial antibodies due to the selective binding aspects that are highly analogous to natural antibodies.Additional work involves transforming the recognition aspects of molecular imprinting into a biomineralization analogue. Biomineralization is the process in which organisms convert freely soluble minerals (namely calcium carbonates and calcium phosphates) into solid parts, such as bones and teeth, at ambient conditions via the influence of organic molecules such as proteins and carbohydrates. The molecular imprinting approach with biomineralization led to limited success but formed the foundation for a more detailed study into the effects of small organic functional groups (COOH-, OH-) on the growth of calcium carbonates and calcium phosphates, the core components of important biocomposites such as bone.In order to study the effects of organic molecules on the calcium based crystals, a mineralization assay was developed in an agarose gel matrix for studying inhibition and growth as influenced by various organic molecule functionalities. The gel mineralization assay is a novel approach in which quantitative and qualitative data could be generated in a high throughput fashion to determine organic molecule mediation of calcium based crystal growth. Such methods provide an approach for eventually providing control in development of synthetic biocomposites with customized materials properties.

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Įvairaus amžiaus kumeliukų ir jaunų žirgų jaukinimas ir treniravimas turi įtakos įvairiems žirgininkystės ir žirginio sporto bei pajėgumo išbandymų aspektams. Jaunų žirgų treniravimo ir jaukinimo metodikų efektyvumas turi ženklią įtaką darbe su žirgais įvykstančius nelaimingus atsitikimus. Taip net 85 procentai nuo bendrai visose gyvulininkystės šakose gaunamų traumų yra būtent žirgininkystės industrijoje gaunamos žmonių traumos ir jų žūtys. (J. Landercasper). Nuo žirgų paklusnumo lygio ar jų neigiamų charakterio bruožų priklauso daugelio žmonių, susijusių su jaunais ir suaugusiais žirgais, sveikata ar net gyvybė. Su žirgais kasdien dirba ir yra jų įtakos sferoje kalviai, kaustantys žirgus, veterinarijos gydytojai, atliekantys pačias įvairiausias neretai skausmingas žirgams procedūras, žirgų treneriai, bei sportininkai ir laisvalaikį praleidžiantys žirgų mėgėjai. Reikia pažymėti, kad su žirgais dirba, sportuoja, juos prižiūri įvairiausio amžiaus žmonės. Pradedant penkiamečiais vaikais ir baigiant senjorais. Tai kelia papildomus reikalavimus jaunų ir suaugusių pačių įvairiausių arklių veislių bei panaudojimo krypčių žirgų pratinimui ir ugdymui. Darbo tikslas yra nustatyti imprintingo įtaką Trakėnų veislės kumeliukų charakteriui ir tolimesniam jo ugdymui. Šiam tikslui buvo iškeltos atitinkamos darbo užduotys: išanalizuoti kumelių laikymo, šėrimo ir kergimo sąlygas Vilniaus ir Nemuno žirgynuose; įvertinti kumelių ir kumeliukų elgesį po kumeliavimosi; išanalizuoti... [toliau žr. visą tekstą] / Of all ages in foals and young horses training has an impact on different horse and equestrian trials and capacity aspects. Young horse training techniques have a significant impact on the efficiency of the work of riding accidents that occur. As many as 85 percent of the total in all livestock sectors received injuries are exactly the equestrian industry people received injuries and deaths. (J. Landercasper). From horse obedience class or negative character of many people associated with the young and adult horses, health and even life. With riding daily work and their sphere of influence, blacksmiths, perishing horses, veterinarians perform a whole range of often painful procedures for horses, horse trainers, and athletes and spend their leisure horse lovers. It should be noted that the horses work, sports, supervised by people of all ages. Starting with five year children and ending with seniors. This puts additional requirements of young and adult a wide variety of horse breeds and horse use directions habituating and education. The aim of this set Imprinting effect Trakehner breed foals character and its further development. Work to achieve the following tasks are: analyze mares storage, feeding and mating conditions for Vilnius and Nemuno for stud; evaluate the mares and foals behavior after foal; to analyze the influence of foal imprinting method for shaping behavior. It was found that in order to achieve good sports results, it is appropriate to apply foals Imprinting... [to full text]

High throughput transcriptomic analyses have realized us with the fact that eukaryotic genome encodes thousands of noncoding RNAs (ncRNAs) with unknown function. In my thesis, I sought to address epigenetic regulation of transcription by ncRNA using the Kcnq1 imprinted cluster as a model system. Genomic imprinting is an epigenetic phenomenon whereby one of the parental alleles is silenced by epigenetic mechanism in a parent of origin-specific manner. A long ncRNA Kcnq1ot1 regulates imprinting of nearly 8 protein coding genes in the Kcnq1 imprinted cluster. Expression of Kcnq1ot1 is restricted to the paternal chromosome while that of protein-coding genes to the maternal chromosome. Kcnq1ot1 is a 91kb long, moderately stable, nuclear localized and RNAPII encoded transcript. We demonstrated that Kcnq1ot1 RNA itself mediates lineage specific silencing on the paternal chromosome by interacting with chromatin and recruiting the repressive chromatin modifiers to the imprinted gene promoters. Previously we identified an 890bp silencing domain (SD) at the 5´end of the Kcnq1ot1 RNA which is responsible for gene silencing. Targeted deletion of the 890SD in mouse resulted in specific loss of silencing of ubiquitously imprinted genes. We have further shown that Kcnq1ot1 interacts with Dnmt1 and recruit Dnmt1 at the somatic DMRs flanking some of the ubiquitously imprinted genes. We next addressed the stability of the Kcnq1ot1 mediated epigenetic silencing using transgenic mouse where we have conditionally deleted the Kcnq1ot1 RNA at different developmental stages and we found that Kcnq1ot1 RNA is required to maintain the silencing of the ubiquitously imprinted genes. In addition, DNA methylation, which controls imprinting of the ubiquitous genes require Kcnq1ot1 for its maintenance. To characterize the ncRNAs that mediate gene regulation through chromatin interaction we have isolated chromatin associated RNAs (CARs) from sucrose gradient fractioned chromatin. High-throughput sequencing of the CARs resulted in the identification of the 141 intronic and 74 intergenic regions harboring CARs. We characterized one of the intergenic CARs which regulate the transcription of the two neighboring genes by modulating the chromatin marks. In summary current thesis has uncovered unprecedented role of ncRNAs in gene expression via chromatin level regulation.

Currently, very little information is available for an in-depth understanding of the molecular binding interactions with molecularly imprinted polymers (MIPs). To address this issue MIPs that have high binding affinities for their template compounds were made so that the nature of these interactions could be elucidated using spectroscopic techniques. 12 functional MIPs were prepared using a series of azobenzene and anthracenyl derivatives as the templates. Affinities of these MIPs for the corresponding templates and analogues were determined by performing batch and competitive binding tests. It was found that extensively conjugated compounds that contain at least two OH groups, an electron-withdrawing substituent and have limited conformational freedom were effective templates. The most efficient MIP, M34, was prepared with 4-[(4-nitrophenyl)azo]-1,2-benzenediol (12). M34 exhibited high affinities for azobenzene derivatives of catechol, and bound those that did not contain non electron-withdrawing substituents more specifically. M34 did not lose affinity for 12 in the presence of analogues, and vice versa, in competitive binding tests. These observations suggested a distribution of different binding sites on M34. M34 bound substrates rapidly, which was attributed to its highly porous polymer matrix giving ready access to binding sites. Formation of the porous matrix was facilitated by the use of DMF as the porogen in the preparation of M34. DMF is not a conventional choice of porogen because use of such highly polar H-bonding solvents is thought to disrupt complexation between template and polymer precursors, which is required for the formation of binding sites. Significant changes in the wavenumbers and the intensities of absorption bands assigned to the catechol substructure of 12 were observed in the FT-Raman spectra of 12 bound to M34. These findings suggested that the catechol substructure was responsible for interactions of 12 with M34 that are critical to rebinding and imprinting. In-situ analyses of dithranol (8) being removed from and bound to its MIP, M23, were performed using ATR-IR spectroscopy. Only one band, assigned to the aromatic substructure of 8, was not obstructed by solvent bands in the spectra of unwashed M23 and washed M23 that was treated with the rebinding solution. The wavenumbers of the corresponding bands in the two spectra were significantly different. This observation suggested that there were differences in the vibrational characteristics of 8 bound to M23 under the two conditions. Evidence was found for H-bonding between OH groups of 8 and C=O group of methacrylic acid using transmission FT-IR spectroscopy. However, no evidence was found that showed significant interactions between 12 and 2-vinylpyridine. Methacrylic acid and 2-vinylpyridine were used as the functional monomers in the preparations of M23 and M34. The FT-IR spectra of mixtures of 12 and 4-vinylpyridine showed three new bands assigned to H-bonded OH stretches. These observations indicated that 4-vinylpyridine H-bonds with 12, and would be a more effective functional monomer than 2-vinylpyridine in the preparation of the MIPs for 12. Titration of 12 with 2-vinylpyridine was analysed by �H NMR spectroscopy. Only small changes to the signals of the corresponding compounds were observed. This lack of change was attributed to the use of d₇DMF, which would compete against 2-vinylpyridine for H-bonding interactions. The findings made using ATR-IR spectroscopy and FT-Raman were novel because previously reported data on bound templates obtained using the corresponding techniques did not show changes in the vibrational characteristics of templates as they bind to MIPs. This investigation has shown that rebinding and spectroscopic studies can provide information about the nature of the binding interactions in MIPs.

Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 94-100). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Also available in print.