Made available in DSpace on 2017-07-10T17:37:50Z (GMT). No. of bitstreams: 1 Luiz Roberto_Faganello.pdf: 3165307 bytes, checksum: 227415100c749ddca305fcc14c6d386b (MD5) Previous issue date: 2012-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / It was developed a study on vegetative propagation on the rooting of Cordia trichotoma semi-woody in Summer and Fall of 2011. Therefore this study aimed to evaluate the effects of different concentrations of IBA (indolbutiric acetic) and NAA (naphthalene acetic) acids on the rooting and establishment of Cordia trichotoma semi-woody cuttings gathered from the sprout of Cordia trichotoma seedlings. To accomplish the objective of this study, two experiments were conducted. The first experiment considers the effect of different concentrations of IBA (Indolbutiric) and NAA (naphthalene acetic) acids on the rooting of Cordia trichotoma stem cutting gathered from the sprout of Cordia trichotoma seedlings produced by seeds, in February 2011, using micro sprinkler irrigation, eight times a day. Cordia trichotoma seedlings were produced by seeds constituting a miniclonal garden with subsequent pruning of the aerial part. Sprouts were harvested resulting in semi-woody cuttings with 12.0 cm long and 5.5 mm in diameter and a pair of leaves in the apical portion reduced in a half. The treatments consisted of fast immersion of the cuttings base in IBA and NAA acids in concentrations of 0, 2.000, 4.000, 6.000, 8.000 mg i.a. L-1 in a randomized block design with factorial arrangement 2 x 5. After 60 days of cutting, rooting percentage, roots number and length, sprouting percentage, the number of shoots and new leaves were evaluated as well as the survival and mortality. When there were differences, the averages were compared by F test at 5 % probability. For concentrations, it was used a polynomial regression analysis to 1 % by F test. The vegetal regulator IBA at a concentration of 8.000 mg L-1 showed higher cutting rootings. The cutting originated from seedlings produced by seeds must be better investigated as an alternative to the vegetative propagation of the species in Summer. The second experiment describes the effect of different concentrations of IBA (Indolbutiric acetic) and NAA (naphthalene acetic) acids on the rooting of stem cuttings gathered from the sprout of Cordia trichotoma seedlings in May 2011, produced by seeds using intermittent mist. Cordia trichotoma seedlings were produced by seeds constituting a miniclonal garden with subsequent pruning of the aerial part. Sprouts were harvested, from the pruning of the previous harvest, resulting in semi-woody cuttings with 12.0 cm long and 5.5 mm in diameter and a pair of leaves in the apical portion reduced in a half. The treatments consisted of fast immersion of the cuttings base in IBA and NAA acids in concentrations of 0, 2.000, 4.000, 6.000, 8.000 mg i.a. L-1 in a randomized block design with factorial arrangement 2 x 5. After 70 days of cutting, rooting percentage, roots number and length, sprouting percentage, the number of shoots and new leaves were evaluated as well as the survival and mortality. When there were differences, the averages were compared by F test at 5 % probability. For concentrations, it was used a polynomial regression analysis to 1 % by F test. The use of plant growth regulator IBA resulted in increased callus formation in cuttings. The cuttings originated from seedlings produced by seed must be further investigated as an alternative to vegetative propagation of the species for this time of year. / Desenvolveu-se um estudo para propagação vegetativa a partir de miniestacas de louro-pardo (Cordia trichotoma Vell. Arrabida ex Steudel) com a coleta dos propágulos no verão e outono de 2011. Assim o presente trabalho teve por objetivo avaliar os efeitos de diferentes concentrações do ácido indolbutírico (IBA) e do ácido naftalenoacético (NAA) no enraizamento e estabelecimento de miniestacas coletadas de brotações de mudas de louro-pardo. Para atender o objetivo deste trabalho, foram realizados dois experimentos. O primeiro experimento aborda o efeito de diferentes concentrações do IBA e NAA no enraizamento de miniestacas caulinares coletadas de brotações de mudas de louro-pardo produzidas por sementes, no mês de fevereiro de 2011, com o uso de irrigação por micro-aspersão, oito vezes ao dia. As mudas de louro-pardo foram produzidas através de sementes, selecionadas e constituindo um jardim miniclonal com posterior poda da parte aérea. As brotações foram colhidas resultando em miniestacas com 12,0 cm de comprimento, 5,5 mm de diâmetro e um par de folhas na porção apical reduzido pela metade. Os tratamentos compreenderam a imersão rápida da base das estacas em ácido indolbutírico e ácido naftalenoacético nas concentrações de 0, 2.000, 4.000, 6.000, 8.000 mg i.a. L-1 em delineamento de blocos casualizados com arranjo fatorial 2 x 5. Após 60 dias do estaqueamento foram avaliados a porcentagem de enraizamento, o número e comprimento das raízes, a porcentagem de brotações, o número de brotos e folhas novas, a porcentagem de estacas com calos, assim como a sobrevivência e mortalidade. Quando da existência de diferenças as médias foram comparadas pelo teste F a 5 % de probabilidade. Para concentrações, utilizou-se a análise de regressão polinomial a 1 % pelo teste F. O regulador vegetal IBA na concentração de 8.000 mg L-1 promoveu maior enraizamento de miniestacas. A estaquia oriunda de mudas produzidas por sementes deverá ser melhor investigada como alternativa para a propagação vegetativa da espécie com coleta de miniestacas no verão. O segundo experimento descreve o efeito de diferentes concentrações do IBA e NAA no enraizamento de miniestacas coletadas de brotações das mesmas mudas de louro-pardo, no mês de maio de 2011, com o uso de nebulização intermitente. As brotações foram colhidas, a partir da poda da coleta anterior, resultando em miniestacas com 12,0 cm de comprimento, e 5,5 mm de diâmetro e um par de folhas na porção apical reduzida pela metade. Os tratamentos compreenderam a imersão rápida da base das estacas em ácido indolbutírico (IBA) e ácido naftalenoacético (NAA) nas concentrações de 0, 2.000, 4.000, 6.000, 8.000 mg i.a. L-1 em delineamento de blocos casualizados com arranjo fatorial 2 x 5. Após 70 dias do estaqueamento foram avaliados a porcentagem de enraizamento, o número e comprimento das raízes, a porcentagem de brotações, o número de brotos e folhas novas, a porcentagem de estacas com calos, assim como a sobrevivência e mortalidade. Quando da existência de diferenças, as médias foram comparadas pelo teste F a 5 % de probabilidade. Para concentrações, utilizou-se a análise de regressão polinomial a 1 % pelo teste F. O emprego do regulador vegetal IBA resultou em maior calogênese média em miniestacas. A estaquia oriunda de mudas produzidas por sementes deverá ser melhor investigada como alternativa para a propagação vegetativa da espécie nesta época do ano.

Or, Pui Ying. / "July 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Abstracts in English and Chinese. / Acknowledgments / Table of Content / List of Figures / List of Tables / List of Publications / Chapter Chapter 1 - --- Background of LDO Research / Chapter 1.1 --- Structure of a LDO --- p.1-1 / Chapter 1.2 --- Principle of Operation of LDO --- p.1-2 / Chapter 1.3 --- Steady-State Specification of LDO --- p.1-3 / Chapter 1.4 --- High-Frequency Specification of LDO --- p.1-3 / Chapter 1.5 --- Dynamic Specification of LDO --- p.1-4 / Chapter 1.6 --- An Advanced LDO Structure --- p.1-4 / Chapter 1.7 --- Contribution and Outline of the Thesis --- p.1-5 / References --- p.1-6 / Chapter Chapter 2 - --- PSRR Analysis / Chapter 2.1 --- Modeling of the PSRR of LDO --- p.2-3 / Chapter 2.2 --- Analysis of LDO Circuit Using Proposed Modeling --- p.2-6 / Chapter 2.3 --- Conclusion of Chapter --- p.2-12 / References --- p.2-13 / Chapter Chapter 3- --- An Output-Capacitorless LDO with Direct Voltage-Spike Detection / Chapter 3.1 --- Analysis of Output-Capacitorless LDO --- p.3-5 / Chapter 3.2 --- LDO with Proposed Voltage-Spike Detection Circuit --- p.3-7 / Chapter 3.3 --- Experimental Results --- p.3-15 / Chapter 3.4 --- Conclusion of Chapter --- p.3-21 / References --- p.3-22 / Chapter Chapter 4 - --- A LDO with Impedance Adjustment and Loop-Gain Boosting Technique / Chapter 4.1 --- Proposed LDO --- p.4-3 / Chapter 4.2 --- Experimental Results --- p.4-7 / Chapter 4.3 --- Comparison --- p.4-11 / Chapter 4.4 --- Conclusion of Chapter --- p.4-12 / Reference --- p.4-13 / Chapter Chapter 5 - --- Conclusion and Future Work

Biofilms are a crucial adaptation for bacterial survival against stresses from external environments. Biofilms are adherent colonies of sessile bacteria embedded within a self-produced matrix. Bacterial control over formation, maintenance, and response to external stresses are strictly regulated. However, complexities of intracellular signaling for biofilm regulation are still not fully understood. In this thesis, I report on two distinct regulatory systems important for biofilm formation in the opportunistic pathogen Pseudomonas aeruginosa. The first regulatory system I report on is the two-component system TctD-TctE. This system is involved in regulating the uptake of tricarboxylic acids such as citric acid and is involved in biofilm-specific susceptibility to aminoglycoside antibiotics. Here I describe work I performed characterizing the involvement of TctD-TctE in biofilm development when citric acid is present as a carbon source in nutrient media. In further characterizing a previously observed aminoglycoside susceptibility, I found that a strain with a deletion of TctD-TctE (ΔtctED) has a heightened accumulation of tobramycin in its biofilms when grown in the presence of citric acid. In ΔtctED, I determined that there was an inhibition of overall cell growth when citric acid was present in nutrient media. Additionally, in the presence of citric acid, ΔtctED displayed high levels of biofilm formation. This contrasted with normal biofilm development observed in the PA14 wild type strain where biofilm mass was reduced in the presence citric acid. The second project of this thesis reports on a novel regulatory small RNA, the Small RNA Regulator of Biofilms (SrbA). SrbA was found to be unique to P. aeruginosa and displayed no homology with any other sequenced bacterial species. I found that loss of SrbA resulted in a significant reduction in biofilm mass. Subsequently, loss of SrbA also leads to attenuation of P. aeruginosa pathogenicity in Caenorhabditis elegans nematodes. Bacterial biofilms possess specific regulatory programs that are still just being appreciated for their complexity. This thesis work adds to our understanding of biofilm regulation by studying roles of the two-component system TctD-TctE and the small RNA SrbA in P. aeruginosa.

Conidiation is a common and critical asexual reproductive mode in fungi. The ascomycetes, the largest group in the kingdom Fungi undergo conidiation. The wide array of morphological difference in a conidiophore and conidial size, shape, and cellular organization demonstrates the importance of evolution in driving the morphological and functional diversity. An important unanswered question is how these conidiation processes evolve. We hypothesized that a conidiation regulatory pathway was present in the ancestral species, and became specialized in the extant species to lead to morphological and functional diversity. To address this hypothesis we assessed the conserved function of conidiation regulators in two distantly related ascomycetes, Aspergillus nidulans and Neurospora crassa. Using sequence similarity analysis, N. crassa orthologs were characterized to seven main conidiation regulatory genes in A. nidulans (fluG, flbC, flbD, abaA, wetA, medA, and stuA). Expression of the N. crassa orthologs complemented defective conidiation in the A. nidulans fluG, flbD, wetA, medA, and stuA mutants. In contrast, abaA and flbC and the N. crassa orthologs did not share conserved biochemical function. Taken in context of other recent studies of conidiation regulators, there are four distinct evolutionary patterns: (i) Non-homologous genes with analogous roles in conidiation (‘brlA’ and ‘fl’), (ii) Orthologs with retained biochemical function that lack analogous role in conidiation (‘fluG’, ‘flbD’, and ‘wetA’), (iii) Orthologs with retained biochemical function and analogous roles in conidiation (‘medA’ and ‘stuA’), and (iv) Orthologs with biochemical function not conserved but with analogous roles in conidiation (‘abaA’ and ‘flbC’). These studies set the stage for long-term studies of how evolution proceeded during the evolution of conidiation at different levels of phylogenetic diversity. An understanding of how evolutionary mechanisms shape the dynamics of developmental pathways will be significant for our understanding of fungal evolution of other novel adaptations such as pathogenesis.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 130-148). Also available on the Internet.

Chromatin is a multi-layered structure composed of DNA, nucleosomes, histone modifications, and associated proteins that critically affects genome function. Recently developed sequencing technologies enable genomewide characterization of certain aspects of chromatin structure, including nucleosome positioning and histone modifications. However, chromatin proteins present several challenges due to their dynamic nature and variable association with DNA. Chromatin proteins such as Polycomb regulators and heterochromatic factors play critical and global roles in epigenetic repression and hence new approaches are needed for their study. We first sought to identify sequences that recruit Polycomb repressive complex 2 (PRC2) in mammalian cells. We combined chromatin immunoprecipitation with sequencing (ChIP-seq) to map the candidate transcription factor YY1, and found that it does not correlate with PRC2 localization, suggesting that YY1 is not directly involved in PRC2 recruitment. We also identified GC-rich sequences that are necessary and sufficient for PRC2 recruitment. Yet attempts to map additional Polycomb proteins and other repressors using ChIP-seq proved difficult. Since chromatin proteins are often broadly, secondarily or transiently bound to DNA, they are difficult to crosslink. Antibody quality also varies, further hampering ChIP-seq technology. Here, we adapt DamID, a method for mapping chromatin regulators that uses a fusion enzyme and that does not rely on crosslinking or antibodies, for high-throughput sequencing. We show that DamID-seq can be used to globally characterize chromatin repressors in human cells. We used DamID-seq to map the binding of 12 chromodomain-containing and related proteins in K562 cells. We found that these proteins cluster into two modules: 1) Polycombrelated and 2) heterochromatin-related. Polycomb proteins bind developmental genes, while heterochromatin proteins bind broad olfactory receptor (OR) and zinc finger (ZNF) domains. Surprisingly, unlike other Polycomb proteins, CBX2 uniquely binds genes involved with modifying proteins. Our findings advance the model that the genome is compartmentalized into domains, and identify the distinct protein components that associate respectively with Polycomb and heterochromatin domains in human cells. We expect that DamID-seq, along with further advancements in characterizing the three-dimensional organization of chromatin, will bring us towards a better understanding of the role of chromatin in differentiation, development, and disease.

No description available.

Magistrantūros studijų baigiamajame darbe pateikiama 2011–2012 metais Aleksandro Stulginskio universiteto Agronomijos fakulteto Agrobiotechnologijos laboratorijoje tirtų veiksnių, lemiančių sėjamosios kanapės dediferenciacijos indukciją hipokotilių ir skilčialapių kultūroje, tyrimų rezultatai. Darbo objektas – 10 dienų eksplantai auginti MS terpėje su skirtingais augimo reguliatorių kiekiais. Darbo metodai: Sėjamosios kanapės sėklos plautos po tekančiu vandeniu 1 val., 15 min. sterilintos 0,2 % kalio permanganato tirpale, 2 min. laikytos 70 % etanolio vandeniniame tirpale, 9 min. 10 % natrio hipochlorite ir 3 kartus po 5 min. mirkytos distiliuotame vandenyje. Sterilios sėklos daigintos ant MS maitinamosios terpės be augimo reguliatorių, papildytoje 10 g l-1 sacharozės ir 8 g l-1 Difco-Bacto agaru. MS terpėje su skirtingais augimo reguliatorių kiekiais auginta po 60 eksplantų. Kas keturias savaites eksplantai perkelti į šviežią tos pačios sudėties maitinamąją terpę. Vertintas kaliaus susidarymo dažnis (%), šaknų formavimosi dažnis (%), šaknų kiekis iš eksplanto (vnt.) bei ūglių formavimosi dažnis (%). Darbo rezultatai. Įvertinus sėjamosios kanapės kaliaus indukcijos tyrimų rezultatus nustatyta, kad sėjamosios kanapės izoliuoti hipokotilio audiniai nedideliu dažniu geba formuoti kalių ir terpėje be augimo reguliatorių. Naudojant vienos grupės (auksiną arba citokininą) augimo reguliatorių didžiausias kaliaus formavimosi dažnis gautas terpėje, papildytoje 0,5 mg l-¹ α... [toliau žr. visą tekstą] / The master work presents the results of factors affecting Cannabis sativa L. dedifferentiation process in vitro. Research was investigated at the Laboratory of Agrobiotechnology, Faculty of Agronomy of Aleksandras Stulginskis University in 2011 - 2012. Investigation in vitro was carried out with Cannabis sativa L. hypocotyls and cotyledons explants. Object of the work – 10 days explants grown in MS medium with different growth regulators concentrations. Method of the work – Cannabis sativa L. seeds were washed under running water for 1 h and surface sterilized with 0.2 % potassium permanganate for 15 min. sterilized and for 2 min. in 70 % ethanol, then sterilized in 10 % sodium hypochlorite for 9 min. and rinsed 3 times for 5 min. with sterile distilled water. Sterile seeds sprouted on MS nutrient medium without growth regulators, supplemented with 10 g l-1 sucrose and 8 g l-1 Difco Bacto-agar. MS medium with different growth regulators concentrations were grown 60 explants. Every four weeks, explants were transferred to the same composition fresh medium. The callus formation frequency (%), root formation frequency (%), root number of the explant (units) and the frequency of shoot formation (%) were evaluated. The results of the work – Cannabis sativa L. hypocotyls tissues with low frequency can form callus and without growth regulators in the medium. Using a single group of growth regulators (auxin or cytokinin) highest callus formation frequency obtained in the medium... [to full text]

Magistrantūros studijų baigiamajame darbe pateikiami veiksnių, lemiančių pluoštinių linų morfogenezę in vitro, tyrimų duomenys. Darbo objektas – keturios pluoštinių linų veislės 'Dangiai', 'Sartai', 'Snaigiai' ir 'Vaižgantas'. Darbo metodai. Pluoštinių linų morfogenezei somatinių audinių kultūroje tirti naudoti hipokotilio eksplantai. Eksplantai auginti MS terpėje su skirtingais augimo reguliatorių kiekiais auginimo kambaryje. Vertintas pridėtinių pumpurų formavimosi dažnis (%) ir pridėtinių ūglių kiekis iš eksplanto (vnt.). Darbo rezultatai. Egzogeninių augimo reguliatorių priedas indukcijos terpėje daugeliu atvejų skatino tirtų pluoštinių linų veislių ūglių regeneraciją, tačiau optimali šio junginio koncentracija priklausė nuo genotipo. Iš tirtų pluoštinių linų veislių didžiausia morfogenine galia pasižymėjo veislės 'Vaižgantas' izoliuoti hipokotiliai. Priklausomai nuo genotipo ir maitinamosios terpės sudėties pluoštinių linų pridėtinių pumpurų formavimosi procesas hipokotilių kultūroje vyko 2,87-94,50 % dažniu regeneruojant 1,67-6,00 ūglius iš eksplanto. Efektyviam veislės 'Dangiai' ūglių regeneravimui maitinamąją terpę tikslinga papildyti 2,0 mg l-1 BAP + 0,1 mg l-1 NAR bei eksplantus paveikti 4 °C temperatūra 24 valandas. Veislės 'Sartai' izoliuotų hipokotilių audinių antrinę diferenciaciją skatino 72 valandų 7 °C temperatūros poveikis bei citokinino 1,0 mg l-1 2iP priedas maitinamojoje terpėje. Intensyviausiai veislės 'Snaigiai' eksplantai pumpurus formavo maitinamojoje... [toliau žr. visą tekstą] / The master work presents the results of fibre flax morphogenesis in vitro affecting factors. Object of the research − four fibre flax cultivars 'Dangiai', 'Sartai', 'Snaigiai' and 'Vaižgantas'. Research methods. To study fiber flax morphogenesis of somatic tissues hypocotyls were used as explant. Explants were placed on MS medium supplemented with different combinations of growth regulators and cultivated in growth chamber. The percentage of bud regeneration and the number of shoots per explant were evaluated. Research results. Exogenous growth regulators concentration in induction media increased fiber flax shoots regeneration, and therefore specific combination of growth regulators must be designed for each genotype. Among investigated genotypes, the hypocotyls of cultivars 'Vaižgantas' manifested the best morphogenic capability. Depending on genotype and medium composition fiber flax adventitious buds regeneration frequency varied from 2.87-94.50% and the number of shoots per explant reached 1.67-6.0, respectively. Hypocotyls of cultivar 'Dangiai' showed the best response on medium supplemented by 2.0 mg l-1 BAP with 0.1 mg l-1 NAA and pretreated by 4 °C temperature 24 hours. In the presence of only cytokinins, the highest mean value of regenerated shoots was observed on medium supplemented with 1.0 mg l-1 2iP and 72 hours 7 °C temperature pretreatment for hypocotyls of 'Sartai'. Growth regulators combination 2.0 mg l-1 2iP with 0.1 mg l-1 NAA and treatment by 4 °C... [to full text]

Magistrantūros studijų baigiamajame darbe pateikiami sėjamosios kanapės eksplanto tipo ir maitinamosios terpės sudėties poveikio mofogenezei in vitro tyrimų rezultatai. Darbo objektas – sėjamosios kanapės stiebo ir lapkočio segmentai. Darbo metodai: Sėjamosios kanapės eksplantai auginti MS, B5 ir White maitinamosiose terpėse, papildytose įvairiais augimo reguliatorių deriniais. Vertintas kaliaus susiformavimo dažnis (%), ūglių susiformavimo dažnis (%) ir šaknų susiformavimo dažnis (%). Darbo rezultatai. Sėjamosios kanapės morfogenezės procesas didžiąja dalimi priklauso nuo bazinės maitinamosios terpės sudėties. Izoliuoti stiebo segmentai intensyviausiai kalių indukavo bazinėje B5 maitinamojoje terpėje, o lapkočio segmentai − B5 maitinamojoje terpėje, papildytoje 1,0 mg l-1 TDZ + 0,5 mg l-1 NAR arba 1,0 mg l-1 KIN + 0,5 mg l-1 NAR. Pridėtinių ūglių formavimasis intensyviausiai vyko bazinėje B5 maitinamojoje terpėje, papildytoje 1,0 mg l-1 TDZ + 0,5 mg l-1 NAR (iš stiebo segmento audinių) ir 1,0 mg l-1 KIN + 0,5 mg l-1 NAR (iš lapkočio audinių). Izoliuoti stiebo segmentai didžiausiu dažniu šaknis formavo B5 maitinamojoje terpėje, papildytoje 1,0 mg l-1 KIN + 0,5 mg l-1 NAR, o lapkočio segmentai − 1,0 mg l-1 TDZ + 0,5 mg l-1 NAR. Tirti stiebo segmentai pasižymėjo didesne geba formuoti kalių, pridėtinius ūglius ir šaknis nei izoliuoti lapkočio segmentai. / The master work presents the effect of explants type and medium composition on morphogenesis in vitro of hemp. Object of the research – stem segments and leafstalk of hemp. Research methods. To study hemp morphogenesis in vitro hypocotyls and leafstalk were used as explants. Explants were placed on MS, B5 and White media supplemented with different combinations of growth regulators. The percentage of callus formation, shoot induction and root formation were evaluated. Research results. The current study indicates that there is strong medium composition effect on morphogenesis in vitro of hemp. From tested media most intensive callus genesis was observed on B5 medium, but from leafstalk – on B5 medium with 1.0 mg l-1 TDZ + 0.5 mg l-1 NAA or 1.0 mg l-1 KIN + 0.5 mg l-1 NAA. The growth regulators combination 1.0 mg l-1 TDZ + 0.5 mg l-1 NAA on B5 media was the most suitable for stem segments shoots induction while growth regulators combination 1.0 mg l-1 KIN + 0.5 mg l-1 NAA promoted the highest frequency of shoots induction from leafstalk segments. The highest root formation frequency was observed on the same basal medium supplemented with 1.0 mg l-1 KIN + 0.5 mg l-1 NAA from stem segments, but from leafstalk – on B5 medium with 1.0 mg l-1 TDZ + 0.5 mg l-1 NAA. Generally, the stem segments exhibited a higher morphogenic response than leafstalk of hemp.