Ethylene, a plant hormone, plays an essential role in many aspects about plant development, growth, ripening, and senescence. In addition, it also regulates several responses when plants suffer stress from drought, flood, herbivore bites, wound, etc. ACC synthase and ACC oxidase belong to two multigene families. In this study, PCR (polymerase chain reaction) and RACE (rapid amplification of cDNA ends) methods were used to amplify the ACC oxidase sequences in Cattleya bicolor orchid flower. The results show that there exists differences in the 3¡¦-UTR (untranslated region) of orchid gene sequences. Compare the ACC oxidase sequences, including the cDNA ORF (open reading frame) sequences and the amino acid sequences, of several different species, the sequence similarity among the three Laeliinae orchids, namely C.bicolor, C. intermedia, and Laelia anceps, is the highest. The similarity of cDNA ORF sequences and amino acid sequences between orchids and the other plants, such as rice, apple and torenia, is comparatively lower. It was proposed that the protein located in cytoplasma (or in mitochondrial matrix space), agrees with the result from analysis of amino acid hydrophilicity prediction. The ultimate goal of this study is to postpone the flower senescence by the way of plant transfection. In the present findings, it only deals with the cloning and analysis of the ACC oxidase genes in C. bicolor.

Adaptive Cruise Control (ACC), mostly equipped on high end vehicles, is an optional cruise control system which automatically adjusts the vehicle speed and maintains a safe distance ahead. The control strategy for ACC, which has been developed for decades, is still well worth being researched. In this thesis, a hierarchical control system architecture was proposed, which divides the controllers into supervisory ones and vehicle level ones. Three control methods, named linear quadratic regulator (LQR), robust LQR (RLQR), and robust composite nonlinear feedback (RCNF) control, were applied as supervisory controllers respectively. And the active disturbance rejection control (ADRC) was chosen as the vehicle level controller. An electric robotic vehicle was built for demonstration and validation. Simulations and experiments were carried out with detailed discussions, which provide a guidance towards future research. / Thesis / Master of Applied Science (MASc)

Diss.--Philosophie--Oxford--Lincoln College, 1997. / Sources et bibliogr. f. 234-264 (t. 1).

No description available.

Upstream oil and gas production has caused soil salinity problems across western Canada. In this work we investigated the use of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing plant growth-promoting rhizobacteria (PGPR) and the arbuscular mycorrhizal fungus (AMF) Glomus intraradices to enhance the efficiency and feasibility of phytoremediation of saline soils. This work involved laboratory and field research for three sites in south east Saskatchewan, Canada. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.

Upstream oil and gas production has caused soil salinity problems across western Canada. In this work we investigated the use of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing plant growth-promoting rhizobacteria (PGPR) and the arbuscular mycorrhizal fungus (AMF) Glomus intraradices to enhance the efficiency and feasibility of phytoremediation of saline soils. This work involved laboratory and field research for three sites in south east Saskatchewan, Canada. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.

abstract: Many species e.g. sea urchin form amorphous calcium carbonate (ACC) precursor phases that subsequently transform into crystalline CaCO3. It is certainly possible that the biogenic ACC might have more than 10 wt% Mg and ∼ 3 wt% of water. The structure of ACC and the mechanisms by which it transforms to crystalline phase are still poorly understood. In this dissertation our goal is to determine an atomic structure model that is consistent with diffraction and IR measurements of ACC. For this purpose a calcite supercell with 24 formula units, containing 120 atoms, was constructed. Various configurations with substitution of Ca by 6 Mg ions (6 wt.%) and insertion of 3-5 H2O molecules (2.25-3.75 wt.%) in the interstitial positions of the supercell, were relaxed using a robust density function code VASP. The most noticeable effects were the tilts of CO3 groups and the distortion of Ca sub-lattice, especially in the hydrated case. The distributions of Ca-Ca nearest neighbor distance and CO3 tilts were extracted from various configurations. The same methods were also applied to aragonite. Sampling from the calculated distortion distributions, we built models for amorphous calcite/aragonite of size ∼ 1700 nm3 based on a multi-scale modeling scheme. We used these models to generate diffraction patterns and profiles with our diffraction code. We found that the induced distortions were not enough to generate a diffraction profile typical of an amorphous material. We then studied the diffraction profiles from several nano-crystallites as recent studies suggest that ACC might be a random array of nanocryatallites. It was found that the generated diffraction profile from a nano-crystallite of size ∼ 2 nm3 is similar to that from the ACC. / Dissertation/Thesis / Ph.D. Physics 2012

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-07-28T16:35:42Z No. of bitstreams: 1 2016 - Rupila Rami da Silva Goda.pdf: 2862869 bytes, checksum: 8c9a253d8a926ba04221e5ffb1311b81 (MD5) / Made available in DSpace on 2017-07-28T16:35:42Z (GMT). No. of bitstreams: 1 2016 - Rupila Rami da Silva Goda.pdf: 2862869 bytes, checksum: 8c9a253d8a926ba04221e5ffb1311b81 (MD5) Previous issue date: 2016-08-30 / Breast cancer is the second most common cancer worldwide. According to the National Cancer Institute (INCA) in 2014 were diagnosed 52,680 new cases in Brazil, a number that corresponds to a 22% increase over the year 2013. Being responsible for approximately 39% of women's deaths cancer patients. Despite the high incidence rate, mortality from this cancer has declined since the late eighties, thanks to advances in research on methods for early diagnosis. However, correctly diagnosing cancer is a complex and difficult process as a result of the different variables involved. For an accurate diagnosis, a lot of experience and especially it is required, that the classification of clinical staging of tumor (cancer stage) is correct. The conditions used traditional classification systems are complex and often offer limitations. As is the case of mammography technique, widely used, it is not as effective for women with dense breasts, surgically altered, or under 40 years. Thus, it becomes necessary to develop integrated systems that combined with the professionals in the field experience, allows performing accurate diagnosis in detecting breast cancer. The objective of this study is to apply the technique SVM (Support Vector Machine), so as to assist in the diagnostic interpretation of microcalcifications detected on screening mammography. The data set used consisted of 961 samples of mammograms, obtained from the Radiology Institute of the University of Erlangen Nuremberg. In this set we have information on the age of the patient, BI-RADS (Breast Imaging Reporting and Data System), shape, mass, density and severity (benign | malignant) of microcalcifications. The SVM was developed implemented using the R software (R Development Core Team; http: // www.R-project.org/). The data were divided into two groups: the training set consisting of 80% of the samples of mammographic, used to estimate the model parameters and the independent test set, with 20% of the remaining samples, used to measure the performance of SVM . To evaluate the performance of proposed computational model we used the value of the Total Precision or Accuracy (ACC), sensitivity (S) and specificity (E). The results presented by SVM in identifying malignant lesions in patients with calcifications remained between 72.7% and 100%, which shows that they achieved a satisfactory level in relation to other literatures applied / O c?ncer de mama ? a segunda neoplasia mais frequente no mundo. Segundo dados do Instituto Nacional de C?ncer (INCA), no ano de 2014 foram diagnosticados 52.680 novos casos no Brasil, n?mero este que corresponde a um aumento de 22% em rela??o ao ano de 2013. Sendo respons?vel por aproximadamente 39% dos ?bitos das mulheres portadores de c?ncer. Apesar da elevada taxa de incid?ncia, a mortalidade causada por esta neoplasia tem diminu?do desde o final dos anos oitenta, gra?as ao avan?o das pesquisas em m?todos para o diagn?stico precoce. No entanto, diagnosticar corretamente o c?ncer ? um processo complexo e muito dif?cil em consequ?ncia das diversas vari?veis envolvidas. Para um diagn?stico preciso, exige-se muita experi?ncia e, principalmente, que a classifica??o do estadiamento cl?nico do tumor (est?gio do c?ncer) esteja correta. Os tradicionais sistemas de classifica??o de patologias utilizados s?o complexos e em muitas vezes oferecem limita??es. Como ? o caso da t?cnica de mamografia, que amplamente utilizada, n?o ? t?o eficaz para mulheres com mamas densas, cirurgicamente alteradas ou com menos de 40 anos. Desta forma, torna-se necess?rio o desenvolvimento de sistemas integrados que combinados com a experi?ncia dos profissionais da ?rea, possibilite realizar o diagn?stico preciso na detec??o do c?ncer de mama. O objetivo do presente trabalho ? aplicar a t?cnica SVM (M?quina de Vetor de Suporte), de sorte a auxiliar na interpreta??o diagn?stica das microcalcifica??es detectadas em mamografia de rastreamento. O conjunto de dados utilizado consistiu de 961 amostras de exames mamogr?ficos, obtidos junto ao Instituto de Radiologia da Universidade de Erlangen- Nuremberg. Neste conjunto possu?mos informa??es referentes a idade da paciente, classifica??o BI-RADS ( Breast Imaging Reporting and Data System), forma, massa, densidade e severidade (benigno|maligno) das microcalcifica??o. A SVM desenvolvida foi implementada utilizando-se o software R (R Development Core Team; http:// www.R-project.org/ ) . Os dados foram divididos em dois grupos: o conjunto de treinamento composto por 80% das amostras de exames mamogr?ficos, usado para estimar os par?metros do modelo e o conjunto de teste independente, com 20% das amostras restantes, utilizado para mensurar a performance da SVM. Para avaliar o desempenho do modelo computacional proposto foram utilizados o valor da Precis?o Total ou Acur?cia (ACC), Sensibilidade (S) e Especificidade(E). Os resultados apresentados pela SVM na identifica??o das les?es malignas em pacientes portadores de microcalcifica??es se mantiveram entre 72,7% e 100% o que demonstram que os mesmos alcan?aram um grau satisfat?rio em rela??o com outras literaturas aplicadas

A new paradigm for the formation of calcified skeletons suggests mineralization proceeds through amorphous calcium carbonate (ACC) precursors. The implications of this strategy in carbonate crystallization are widespread, particularly for understanding factors controlling impurity and isotopic signatures in calcium carbonates. The first chapter is a literature review of the biomineralization processes used by two important model organisms: the sea urchin larva and the foraminifera. Sea urchin larvae provide a thoroughly studied example of mineralization by an ACC pathway that is under biological control through regulation of protein chemistry and the local mineralization environment. A review of how foraminifera produce their test structures is also examined to explore the question of how organisms regulate the Mg content in proportion to the temperature their environments of formation. The second chapter demonstrates that acidic biomolecules regulate the composition of ACC for a suite of model carboxylated molecules. The physical basis for the systematic trend in Mg content is related to the ability of the affinity of the biomolecule for binding Ca versus Mg. The third chapter builds on these findings to explore the transformation of Mg-rich ACC precursors to calcites of exceptionally high Mg-contents that could not be produced by classical step-dominated growth processes. The data indicate that these materials are likely a result of a nucleation-dominated pathway. The final, fourth chapter develops Raman spectroscopy-based calibrations for determining Mg contents in ACC. The calibrations are based upon peak position or peak width of the carbonate υ₁ stretch. / Ph. D.

Recent advances in high-resolution analytical methods have brought about a paradigm shift in our understanding of how crystalline materials are formed. The scientific community now recognizes that many earth materials form by multiple pathways that involve metastable intermediates. Biogenic calcium carbonate minerals are now recognized to develop by aggregating molecules or clusters to form amorphous phases that later transform to one or more crystalline polymorphs. Amorphous calcium carbonate (ACC) is now recognized as a precursor to CaCO₃ biominerals in a wide variety of natural environments. Recent studies suggest an ACC pathway may imprint a different set of dependencies from those established for classical growth processes. Previous ACC studies provided important insights, but a quantitative understanding of controls on ACC composition when formed at near-physiological conditions is not established. The Mg content of ACC and calcite is of particular interest as a minor element that is frequently found in final crystalline products in calcified skeletons. This three-part dissertation investigated biological and well-characterized synthetic ACC using high-energy x-ray methods, Raman spectroscopy, and mechanical tests. The findings establish chemical and physical properties of ACC in the exoskeleton of crustaceans and show Mg and P levels are tuned in the mineral component to optimize exoskeleton function that could be sensitive to ecological or environmental conditions. Calcite and chitin crystallinity exhibit a similar body-part-specific pattern that correlates directly with the mechanical strength of the exoskeleton. Insights from this study suggest precise biological control of ACC chemistry in the to regulate exoskeleton properties. Laboratory measurements using quantitative methods and compositions that approximate the physiological conditions of crustaceans, demonstrate at least two types of ACC are formed by controlling Mg concentration and alkalinity. We also find temporal changes in the short-range ordering of ACC after precipitation that is dependent upon carbonate content. The findings from this study provide a quantitative basis for deciphering relationships between ACC structures, solution chemistry, and the final transformation products under biologically relevant conditions. / Ph. D. / With the development of new imaging methods for nano-scale materials, scientists across diverse disciplines have recognized that many earth materials can form complex shapes by the formation and aggregation of nanocrystals or structureless (amorphous) particles. Biological minerals, such as shells and skeletons, are well-documented to form CaCO₃ via both of these attachment pathways, particularly amorphous calcium carbonate (ACC). However, little is known about the ACC properties and the factors that determine the final composition of skeletal minerals. This three-part dissertation focuses on ACC and calcite in the exoskeletons of crustaceans to understand how animals form composite exoskeletons of calcium carbonate minerals. This knowledge is important because CaCO₃ minerals are the primary component of the shells and skeletons of many economically important marine species. These minerals are also prevalent in the geological record as roadmaps for the evolutionary record. Amorphous and crystalline forms of CaCO₃ are also used as inert 'filler' materials for pharmaceutical products. By designing a series of experiments to characterize ACC in exoskeletons from lobsters and crabs, one part of the dissertation shows relationships between chemical composition and physical behavior of the materials. Building on this biomineral information, a separate experimental study synthesizes ACC under near-physiological conditions to show how amorphous CaCO₃ forms under controlled conditions. The findings have far-reaching consequences for understanding the complex chemistry that underlies the formation of calcium carbonate as a component of shells and skeletons, and what physical properties are optimized by the composition of these materials.