Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-03-17T13:02:31Z No. of bitstreams: 1 2016 - Lana Claudia Barros Bezerra.pdf: 1532524 bytes, checksum: 3c10f97f96f82861ffd6b1d6d91cc04f (MD5) / Made available in DSpace on 2017-03-17T13:02:31Z (GMT). No. of bitstreams: 1 2016 - Lana Claudia Barros Bezerra.pdf: 1532524 bytes, checksum: 3c10f97f96f82861ffd6b1d6d91cc04f (MD5) Previous issue date: 2016-05-05 / This dissertation it is based in research quali-quantitative which focused on graduates of Veterinary Medicine perception, course egress of Agricultural Science Graduation (ASG) of Federal Rural University of Pernambuco (UFRPE) who carried out the academic degree in the period of 2010.1 to 2013.2. The theoretical and empirical research identify the contributions of docent formation brought to academic and professional life in view of the influence of humanistic, pedagogical and environmental design a degree course in agrarian area should promote those who resort to this. Interested in this research to investigate the ASG course contributions to the veterinarian in order to understand the expectations and conceptions of licensed graduates on the teaching profession. The subjects were twenty-one licensed veterinarians and two coordinators. Our problem raised concerns about the training that the said course enabled the students of Agricultural Sciences, focusing on Veterinary Medical of UFRPE. Data collection was carried out in four stages: bibliographical survey of theorists who elaborates on the theme; documentary consulting the files of graduates; consultation with the Political Pedagogical Project ASG and resolutions UFRPE with application of questionnaires to thirty-four semi-structured interviews with graduates and three subjects surveyed. These tools made it possible to quantify and identify the profile of graduates, seizing their perception of the current proposal with the triangulation of the looks of the students as respondents, the coordinators as informants and the researcher. The research allowed important contributions and intentions were identified in the proposal of the Pedagogic Political Project of the degree that guide to building a practice based on humanistic relations for the performance of these graduates in their various contexts / Esta disserta??o se fundamenta em uma pesquisa de abordagem quali-quantitativa que voltou-se para conhecer a vis?o dos graduados em Medicina Veterin?ria, egressos do Curso de Licenciatura em Ci?ncias Agr?colas - LCA, da Universidade Federal Rural de Pernambuco (UFRPE), que realizaram a forma??o acad?mica na licenciatura no per?odo de 2010.1 a 2013.2. A pesquisa te?rico-emp?rica identificou a contribui??o que a forma??o docente trouxe para a vida acad?mica e profissional tendo em vista as influ?ncias da concep??o humanista, pedag?gica e socioambiental que um curso de Licenciatura na ?rea agr?ria deve promover aqueles que recorrem a este. Interessou a presente pesquisa investigar as contribui??es do curso LCA para o m?dico veterin?rio, de forma a compreender as expectativas e concep??es dos egressos licenciado sobre a profiss?o docente. Os sujeitos desta pesquisa foram vinte e um m?dicos veterin?rios licenciados e dois Coordenadores. Nossa problem?tica suscitou inquieta??es a respeito da forma??o que o citado curso possibilitou aos alunos das Ci?ncias Agr?rias, com foco nos M?dicos Veterin?rios da UFRPE. A coleta de dados foi realizada em quatro momentos: Levantamento bibliogr?fico dos te?ricos que discorre sobre a tem?tica, consulta documental aos dossi?s dos egressos, consulta ao Projeto Pol?tico Pedag?gico do LCA e resolu??es da UFRPE, aplica??o dos question?rios a trinta e quatro egressos, entrevistas semi-estruturada com tr?s sujeitos pesquisados. Esses instrumentos possibilitaram quantificar e identificar o perfil dos egressos, apreendendo sua percep??o em rela??o a proposta do curso com a triangula??o dos olhares dos discentes como respondentes, os coordenadores como informantes e o pesquisador. A pesquisa permitiu que fossem identificadas importantes contribui??es e inten??es contidas na proposta do Projeto Pol?tico Pedag?gico da Licenciatura que orientam para a constru??o de uma pr?tica pautada em rela??es humanista para a atua??o desses licenciados em seus diversos contextos

A flavonol specific glucosyltransferase cloned from Citrus paradisi has strict substrate and regio-specificity (Cp3OGT). The amino acid sequence of Cp3OGT was aligned with sequences of an anthocyanidin UDP- dependant glucosyltransferase (UGT) from Clitorea ternatea and a UGT from Vitis vinifera that can glucosylate both flavonols and anthocyanidins. Using homology modeling to identify candidate regions followed by site directed mutagenesis, three double mutations were constructed and biochemically characterized. S20G+T21S mutant protein retained activity with flavonols similar to the wildtype Cp3OGT but the mutant had optimum activity at 60°C and broadened substrate acceptance to include the flavanone naringenin. S290C+S319A mutant protein retained 40% activity with quercetin relative to WT, and had an optimum pH shift. H154Y+Q87I mutant protein was only 10% active with quercetin relative to WT. Docking analysis revealed that H154, Q87 and S20 could be involved in orienting the acceptor molecules within the acceptor binding site whereas S319 and S290 residues are involved in maintaining the active site conformation.

Physical and chemical properties of non-composted spent coffee (CF) and tea (T) suggest they may have applications as soil amendments for improving poor soils. Studies were conducted to determine 1) the effect of amendments on grass growth and soil properties, 2) the effect of incorporation versus surface application of amendments on soil properties, and 3) the effect of amendment application frequency on grass growth and soil properties. In the first study, amendments were mixed with sand and planted to bermudagrass. Treatments included CF, T, and peat moss (PM) mixed with sand, and 100% sand as a control. In the second study, amendments were topdressed onto a sand base with different timings. Pots were either aerified or not. Treatments included T, CF, PM, and a control. Nutrient contents and soil CEC and OM under CF and T treatments were equivalent to or greater than PM treatments. Tea showed comparable grass cover to the PM treatment, while CF showed an inhibitory effect to grass growth in the first year of the study. Aerification showed no benefit. Additionally, a field study was conducted to evaluate CF and T on surface hardness, VWC, and quality after trafficking. Differences were not observed among treatments.

To assess what factors are driving the exponential growth of farmers’ markets in Kentucky, geospatial and statistical analysis of a database of 121 farmers’ markets was conducted. A statewide survey of market leaders and a case study of a single farmers’ market both identified reasons for growing support of farmers’ markets in Kentucky. Market distribution, vendor levels, and gross sales were mapped against a backdrop of county urban classification, median household income, and education levels. Kruskal-Wallace analysis was used to identify if Kentucky’s rural, micropolitan, and metropolitan markets differ significantly in terms of their age, number of vendors, and market sales. Geospatial analysis indicates that farmers’ markets are more concentrated in metropolitan areas of the Commonwealth. However, statistical analysis reveals that farmers’ markets have been established longer in micropolitan areas of the state. Markets across urban classes have significantly different ages and gross sales, but all markets tend to sustain a similar number of vendors. Population levels appear to have the strongest correlation with the variables studied, although education and household median income also may play a role in farmers' market strength. Market stakeholders believe that markets are gaining popularity as consumers become more aware of food safety and environmental problems in the mass market system. Farmers’ markets are considered an important tool for strengthening the local economy, connecting farmers with consumers, and increasing local availability of fresh and nutritious foods.

Ergovaline is produced by the endophyte Neotyphodium coenophialum (Morgan-Jones and Gams) in tall fescue (Schedonorus arundinacea (Schreb.) Dumort. = Festuca arundinacea Schreb.) and is blamed for a multitude of costly livestock disorders. Testing of pastures is common in both research and on farm situations. Since ergovaline is known to be unstable and affected by many variables, the objective of this study was to determine the effect of sample handling and storage on the stability of this compound. Homogeneous milled tall fescue sub-samples were analyzed for ergovaline concentration using HPLC after a range of sample handling procedures or storage. Ergovaline was unstable in milled material after 24 hours in storage, regardless of temperature. The decrease in ergovaline after 24 hours ranged from 17 to 60%. These results show that tall fescue sample handling and storage have a significant effect on ergovaline concentrations. In conclusion, accurate laboratory analysis of ergovaline content may require that samples be transported immediately to the laboratory on ice for immediate analysis. Most laboratories are not equipped for same day analysis, therefore researchers and producers should acknowledge that laboratory ergovaline results may be lower than the actual content in the field.

Loline alkaloids, found in many grass-Epichloë symbiota, are toxic or feeding deterrent to invertebrates. The loline alkaloids all share a saturated pyrrolizidine ring with a 1-amine group and an ether bridge linking C2 and C7. The steps in biosynthesis of loline alkaloids are catalyzed by enzymes encoded by a gene cluster, designated LOL, in the Epichloë genome. This dissertation addresses the enzymatic, genetic and evolutionary basis for diversification of these alkaloids, focusing on ether bridge formation and the subsequent modifications of the 1-amine to form different loline alkaloids. Through gene complementation of a natural lolO mutant and comparison of LOL clusters in strains with different loline alkaloid profiles, I found that lolO, predicted to encode a 2-oxoglutarate-dependent nonheme iron (2OG/Fe) dioxygenase, is required in formation of the ether bridge. Through application of isotopically labeled compound to Epichloë uncinata culture, I established that exo-1-acetamidopyrrolizidine (AcAP) and N-acetylnorloline (NANL) are true pathway intermediates. Application of AcAP to yeast expressing lolO resulted in production of NANL, establishing that LolO is sufficient to catalyze this unusual oxygenation reaction. After ether formation, modifications on the 1-amino group give loline, N-methylloline (NML), N-formylloline (NFL) and N-acetylloline (NAL). A double knockout of lolN, predicted to encode an acetamidase, and lolM, predicted to encode a methyltransferase, produced only NANL. Complementation of the double knockout with wild-type lolN and lolM restored the loline alkaloid profile. These results indicate that LolN is involved in deacetylating NANL to produce norloline, which is then modified to form the other lolines. Crude protein extract of a yeast transformant expressing LolM converted norloline to loline and NML, and loline to NML, supporting the hypothesis that LolM functions as a methyltransferase in the loline-alkaloid biosynthesis pathway. The alkaloid NAL was observed in some but not all plants symbiotic with Epichloë siegelii, and when provided with exogenous loline, asymbiotic meadow fescue (Lolium pratense) plants produced N-acetylloline (NAL), indicating that a plant acetyltransferase converts loline to NAL. I further analyzed the basis for loline alkaloid diversity by comparing the LOL clusters in the Epichloë and Atkinsonella species with different loline alkaloid profiles, and found that LOL clusters changed position, orientation and gene content over their evolutionary history. Frequent, independent losses of some or all late pathway genes, lolO, lolN, lolM and lolP, resulted in diverse loline alkaloid profiles. In addition, phylogenetic analyses demonstrated transspecies polymorphism of the LOL clusters. Based on my findings, I established that in Epichloë and Atkinsonella species the ether bridge is formed on acetamidopyrrolizidine. My study of the loline alkaloid profile of Adenocarpus decorticans (Fabaceae) suggests that these plants probably use a similar strategy at least with respect to ether-bridge formation. Further diversification steps of loline alkaloids in grass-Clavicipitaceae symbiota are carried out by enzymes of both Epichloë species and the host plant. Finally, I present evidence that LOL clusters have evolved by balancing selection for chemical diversity.

Tall fescue is a widely used forage grass in the eastern USA and can form a symbiosis with a fungal endophyte, which can be beneficial for the plant but can cause livestock health issues. Little is known regarding the symbiotic response to predicted climate change. To address this knowledge gap, I analyzed tall fescue variety trial data collected throughout the U.S., exploring relationships between climate variables and yield for two different fescue cultivars that were either endophyte-free or infected. This study showed no endophyte or cultivar effect on fescue yield, but identified temperature, precipitation and location as significant predictors of yield, suggesting that local conditions were more important than endophyte presence or fescue genotype for this dataset. Using a field experiment located in central Kentucky, I quantified the ecophysiological responses of four tall fescue genotypes to endophyte presence, elevated temperature and increased growing season precipitation. In this study, tall fescue genotype was as important as endophyte presence in determining ecophysiological responses to climate change treatments. My thesis illustrates that tall fescue response to climate change will depend on host genetics, the presence and genetics of the fungal endophyte symbiont, and the specific changes to the environment experienced at a site.

The annual Sigmon Farm Tour was started in 1992 as an agricultural education program where students could experience being on a farm with the goal of increasing the agricultural literacy levels of the participants. Every year the entire 4th grade student population of Rockcastle County spends the day touring the farm and participating in experiential mini lessons given by the cooperating farm service and health agencies. The program has continued for 20+ years without an evaluation as to whether it is achieving its objectives. This evaluation will also exhibit the programs strengths and weakness so it can continue to improve. This study utilized the pretest, posttest and delayed posttest to ascertain the agricultural literacy level of the student before the fieldtrip, after participating in the field trip and again 90 days later.

There has been increased interest in utilizing switchgrass (Panicum virgatum) as biomass. There are several challenges to developing this industry, and these have led to the potential use of switchgrass as hay for feeding beef cattle in Kentucky. The effect of increasing maturity on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and nutritive values of switchgrass hay has been well documented, but few in vivo intake and digestibility trials have been conducted to assess this effect on animal performance when feeding beef cattle. Two in vivo intake and digestibility trials were conducted in 2011 in which Angus x Hereford beef steers (200-265 kg) were fed Alamo and Cave-in-Rock switchgrass harvested as late vegetative, boot, and early flowering hay. The objectives of these trials was to evaluate the effect of increasing maturity on apparent dry matter intake (DMI), digestible dry matter intake (DDMI), and dry matter digestibility (DMD); and to discuss potential challenges that producers might face if incorporating switchgrass hay into their forage program for feeding beef cattle. Observed decreases in nutritive value, DMI, DDMI, and DMD indicate that producers should harvest Alamo and Cave-in-Rock switchgrass before it reaches the boot stage of maturity.

Cocoa has been useful in several ways, especially to countries that produce it and consumers all over the world. Its benefits range from improving economies to satisfying millions all over the world who desire one cocoa product or the other. The production of cocoa however is not without its own attendant problems. Aging tree stock, spread of diseases, and production capacity problems are, but a few of many challenges that seed gardens that produce cocoa face. This study investigated the pollination process on selected seed gardens in Ghana, the second largest world producer of cocoa. The purpose of this study was to investigate the artificial pollination process of cocoa on seed gardens in Ghana, and explore ways by which the Lean principle of Value Stream Mapping could be applied in improving the process. The process of pollination was observed on eighteen seed gardens, and a current value stream map depicting the existing process developed to give an indication of the current state of affairs. Subsequently, a future value stream map based on the current map was developed to show aspects of the process that could be improved to enhance the operations of the seed gardens. The future value stream map revealed that operational procedures relating to cleaning and preparation of trees, choosing male and female trees for pollination, harvesting of pollen, and manually pollinating practices presented various avenues for improving the pollination process and hence seed production output.