Two consecutive experiments were conducted to test a hypothesis that mixed grazing outcome is influenced by the type of stocking system applied. The objective of both experiments was to investigate the influence of co-grazing with sheep on cattle liveweight gain (LWG) under continuous (C) and rotational (R) stocking, where sheep weekly liveweight change under the two stocking systems was kept similar. In experiment I nine yearling heifers (266 ± 4.5 kg liveweight) and 27 ewe hoggets (54±0.9 kg liveweight) were continuously stocked for 19 weeks on an irrigated perennial ryegrass-white clover pasture (2.95 ha) maintained at a sward surface height (SSH) of 5cm by adding or removing additional animals in a fixed ratio (1: 1 W⁰.⁷⁵ cattle:sheep). An equal area of pasture was rotationally stocked by a similar group of animals where they received a new area of pasture daily and also had access to the grazed area over the previous 2 days. The size of the new area provided daily was such that the weekly liveweight change of rotationally co-grazed sheep was equal to that of those continuously co-grazed with cattle. Similar groups of animals were used in the second experiment with additional group of 9 heifers grazed alone on C and R pastures. Liveweight of animals was recorded weekly and final fasted weight was determined after 24-hour total feed restriction. SSH on both treatment swards was recorded daily. There were three intake measurement periods spread over the trial period. Organic matter intake (OMI) was predicted from the ratio of N-alkanes in faeces and herbage. Diet composition was determined by dissecting oesophageal extrusa samples. Grazing behaviour (bite rates and grazing time) were also recorded. The mean SSH for C pasture was 5.1±0.09 cm. Overall pre- and post-grazing SSH for R pasture was 15.9 ±0.12 and 5.6 ±0.07 cm, respectively. As determined by the protocol average daily LWG of sheep was similar between C and R (147 (±5.8) vs 138 (±6.7) g day⁻¹; (P>0.05). In contrast, cattle continuously stocked with sheep grew 200 g day⁻¹ slower than those rotationally stocked with sheep (800 (±41.6) vs 1040 (±47.7) g day⁻¹, P<0.0l). R heifers achieved 30 kg higher final fasted liveweight than C heifers (350 vs 381 kg; P<0.01). Overall LWG per ha was also 6 % higher under R than C stocking (674 vs 634 kg ha⁻¹). The OMD of both sheep (73.5 vs 75.8 %) and cattle (75.8 vs 78.0 %) diets was similar under continuous and rotational stocking. There was no significant difference OMI data also concurred with the L WG data (Cattle: 7.94 vs 6.31 (±0.32) kg day⁻¹ (P<0.05); sheep: 1.40 vs 1.44 (±0.04) kg day⁻¹ for Rand C treatments, respectively). There was no difference in clover content of cattle diet under C and R treatments. C heifers had higher number of bites per minute than R heifers (62 vs 56; P<0.05). Proportion of heifers seen grazing (every 15-minute) during four 24-hour observations was greater on C than R pasture (0.44 vs 0.31 (±0.03); P<0.05). The similarity coefficient between sheep and cattle diet was 0.61 and 0.76 under C and R stocking, respectively. The lower daily LWG of C heifers was attributed to (a) the lower SSH under C than R stocking and/or (b) the inability of cattle to compete well with sheep where there is small, continual renewal of resources (C) in contrast to a large periodic renewal under R stocking. This experiment showed that the outcome of mixed gruing can be influenced by the stocking system chosen. But it was not possible to apportion the difference in LWG of cattle between mixed grazing per se and the difference in mean grazed sward height (5.1 for C vs 10.8 cm for R). A second experiment was conducted to determine the relative performance of cattle co-grazed with sheep (CS) and grazed alone (CA) under each stocking system. Hence, there were four treatments. CA- continuous stocking (CA-C), CS- continuous stocking (CS-C), CA- rotational stocking (CAR) and CS- rotational stocking (CS-R). A total area of 4.42 ha was allocated to each stocking system. Under C stocking, 2.95 ha (2/3) was assigned to CS-C and 1.47 ha (1/3) to CA-C, and SSH on both treatments was kept at 4 cm by adding or removing extra animals. Under R stocking, CA-R and CS-R grazed side by side separated by an electric fence. They were given a fresh area daily, the size of which was varied such that the weekly LW change of R sheep was equal to that of the C sheep. CA-R received one-third of the new area though the size was adjusted regularly to achieve the same post-grazing SSH with CS-R. Measurements included: weekly liveweight change, OMI (two periods) and diet composition (using N-alkanes). The mean SSH of CA-C and CS-C swards was 4.27 and 4.26 (±0.02) cm, respectively. CA-R and CS-R swards had mean pre-grazing SSH of 14.9 and 15.2 (±0.08) cm and post-grazing heights of 4.87 and 4.82 cm (±0.03), respectively. The proportion of areas infrequently grazed was higher for CA-C than CS-C swards (0.22 vs 0.17, respectively). C and R sheep daily LWG: 155 (±0.6) and 147 (±0.7) g, and OMI: 1.96 and 2.04 (±0.ll) kg, respectively, were not significantly different. They also had similar diet composition. In comparison, CS-C heifers grew only at 69 % of the daily LWG achieved by CS-R heifers (706 vs 1028 (±72) g; P<0.05). LWG of CA-C and CA-R was 916 and 1022 (±72) g day⁻¹, respectively. The difference in LWG between CS-R and CS-C (D₁) heifers was due to difference in mean sward height, stocking system and mixed grazing, while D₂ (difference in LWG between CA-R and CAC) was due to difference in mean sward height and stocking system. D₁-D₂ (the effect of stocking system on mixed grazing) was 216 g and made up 67 % of the total difference between CS-R and CS-C. There was a significant stocking system-species mixture interaction in the final fasted LW achieved by heifers. Final fasted LW was significantly lower for CS-C than CA-C heifers (283 vs 323 (±9.7) kg), but did not differ between CS-R and CA-R (332 vs 330 (±9.7) kg, respectively). The digestibility of diet OM was similar for both continuously and rotationally stocked sheep (84.4 vs 83.2 %, respectively). Cattle diet OMO was 76.5, 74.7, 79.4 and 77.8 for CA-C, CS-C, CA-R and CS-R respectively (P>0.05). Differences in OMI followed a similar pattern to daily LWG. Mean daily OMI was 8.98, 6.24, 8.80 and 9.45 (±0.40) kg for CA-C, CS-C, CA-R and CS-R, respectively. Clover content of the diet of CA-C heifers was three times higher than that of CS-C heifers (30.7 vs 10.4 % OM; P<0.05); there was no difference in clover content of diets of CS-R and CA-R heifers (21.5 vs 23.9 % OM, respectively). In both stocking systems LWG per ha was higher on CA than CS treatments. These results suggested that the disadvantage of selective clover grazing by sheep outweighed the advantages of sheep grazing around cattle dung patches under continuous stocking. Under rotational stocking, rapid diurnal changes in sward conditions probably limited selective grazing by both sheep and cattle such that there was no disadvantage to CS cattle. The results do not provide a basis for recommending grazing cattle with sheep rather than cattle alone, but do provide some basis for recommending co-grazing of sheep and cattle using rotational rather than continuous stocking.

Alternative grazing systems and pasture types for wool production in the south west of Western Australia were analysed using bio-economic modelling techniques in order to determine their relative productivity and profitability. After reviewing the experimental and modelling literature on perennial pastures and grazing systems, seven case studies of farmers were conducted in order to investigate the practical application of innovative grazing systems and use of perennial pastures. Together these case studies provided information for identifying relevant variables and for calibrating the modelling work which followed. The core of the work lies in a bio-economic model for investigating the comparative value of the three grazing systems and two pasture families mentioned above. A baseline scenario using currently available and reliable scientific data provides baseline results, after which a number of sensitivity analyses provide further insights using variations of four key parameters: persistence, heterogeneity, water soluble carbohydrates, and increased losses. Results show that perennial pastures are in the studied region more profitable than annual pastures. Under current baseline conditions, continuous grazing with perennial pastures is the most profitable enterprise, but this superiority is not robust under parameter variations defined by other scenarios. The more robust solution in terms of enterprise profitability is cell grazing with perennial pastures. The results indicate that intensive grazing systems such as cell grazing have the potential to substantially increase the profitability of grazing operations on perennial pasture. This result is an encouraging one in light of its implications for water uptake and salinity control. It means that economics and land care can go hand in hand, rather than be competitive. It is to be noted that it is the choice of the grazing system in combination with the pasture species, rather then the pasture species itself, that allows for such complementarity between economics and sustainable land use. This research shows that if farmers adopt practices such as cell grazing they may be able to increase the area that they can profitably plant to perennial pasture thus reducing the impacts of dryland salinity. This finding is consistent with the findings of the case studies where the farmers perceived that, provided grazing was planned, increasing the intensity of their grazing management and the perenniallity of their pastures would result in an increase in the profitability of their grazing operation. As a result this research helps to bridge a gap which has existed in this area of research, between the results of scientific research and those reported in practice.

The study was conducted with the objective to evaluate the intensity and frequency of defoliation and the tillering dynamics of ryegrass (Lolium multiflorum Lam.) of stages vegetative and reproductive, under rotational grazing. The interval between grazings was set by the thermal sum required for the appearing of 1.5 ryegrass leave (187.5 ºGD). The experimental design was completely randomized, with two phenological stages and six replicated areas for each stage. In the vegetative stage, the intensity defoliation (54%) it was similar in the different types of leaf blades. In the reproductive stage, the intensity of grazing was higher in leaves growing (78%) in relation to the expanded and senescent leaves (67%). Heifers explored 16.7% more grazing area in the reproductive stage compared to vegetative. The most removal intensity the leaves of expansion and the higher frequency defoliation are compensatory mechanisms used by animals when the ryegrass is located the reproductive stage. The first generation of tillers have greater longevity compared to other generations, contributing 58% of total tillers in the late vegetative stage of ryegrass and 36% of tillers in the last month of pasture utilization. The population of tillers in vegetative and reproductive stages of pasture is maintained stable when the ryegrass pasture is managed in a rotational system, considering the thermal sum of 187.5 ºGD and canopy height in the exit of the animals of the plots around 10 cm. / O trabalho foi realizado com o objetivo de avaliar a intensidade e frequência de desfolhação e a dinâmica de perfilhamento do azevém (Lolium multiflorum Lam.) nos estádios vegetativo e reprodutivo, sob pastejo rotacionado. O intervalo entre pastejos foi estabelecido considerando a soma térmica necessária para a emissão de 1,5 folha de azevém (187,5º GD). O delineamento experimental foi inteiramente casualizado, com dois estádios fenológicos e seis repetições de área para cada estádio. No estádio vegetativo, a intensidade de desfolhação (54%) foi semelhante nos diferentes tipos de lâminas foliares. No estádio reprodutivo, a intensidade de desfolhação foi superior nas folhas em expansão (78%) em relação às folhas expandidas e senescendo (67%). As bezerras exploraram 16,7% a mais a área de pastejo no estádio reprodutivo em relação ao vegetativo. A maior intensidade de remoção de folhas em expansão e a maior frequência de desfolhação são os mecanismos compensatórios utilizados pelos animais quando o azevém encontra-se no estádio reprodutivo. A primeira geração de perfilhos tem maior longevidade em relação às demais gerações, contribuindo com 58% do total de perfilhos no final do estádio vegetativo do azevém e 36% do total de perfilhos no último mês de utilização da pastagem. A população de perfilhos nos estádios vegetativo e reprodutivo do pasto é mantida estável quando a pastagem de azevém é manejada em sistema rotacionado, considerando a soma térmica de 187,5 ºGD e com a altura do dossel na saída dos animais das parcelas ao redor de 10 cm.

Submitted by Josué Cardoso dos Santos (josuesantosunesp@gmail.com) on 2018-09-10T18:36:37Z No. of bitstreams: 1 Tese_Final_Josue_Cardoso_Santos.pdf: 78449557 bytes, checksum: 4515b9cb7cc346753f7e9682b8e037de (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-09-10T18:47:05Z (GMT) No. of bitstreams: 1 santos_jc_dr_guara.pdf: 78449557 bytes, checksum: 4515b9cb7cc346753f7e9682b8e037de (MD5) / Made available in DSpace on 2018-09-10T18:47:05Z (GMT). No. of bitstreams: 1 santos_jc_dr_guara.pdf: 78449557 bytes, checksum: 4515b9cb7cc346753f7e9682b8e037de (MD5) Previous issue date: 2018-07-04 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nowadays, despite the technological development experienced by science in general, a fact especially evident by the available powerful computer machines, the analytical and semi-analytical methods to study different space problems are still of great importance in the fields of astrodynamics and celestial mechanics. From the physical understanding of the motion of celestial bodies to the planing and designing of space missions, the use of mathematical models to deal with a very large number of contemporary problems plays a fundamental role in the progress of human knowledge. In this context, the present thesis presents the use of different mathematical techniques to deal with different various and current problems in astrodynamics and celestial mechanics. The studies developed throughout this work are applicable to both areas. The topics studied are the following ones: (1) The development of disturbing potentials using the double-averaging process, in order to be included in the Lagrange planetary which are numerically integrated to study features of orbits around Mercury and the Galilean moon Callisto; (2) The use of different perturbation integrals, techniques to identify and map different perturbations present in a planetary system, with focus on the analysis of systems of Giant planets with their massive moons; (3) The use of the concept of intermediary Hamiltonian and the use of a canonical transformation called elimination of the parallax, both to deal with binary systems in the context of the roto-orbital dynamics, this one as an approach of the fulltwo body problem; (4) An updated analysis of Gauss variational equations to study quasisatellite orbits around the Martian moon Phobos and with analytical predictions made after obtaining linear and averaged equations of motions. Therefore, this thesis intend not only to provide important analysis and results for each specific problem which it deals with along its pages, but also seeks to highlighting the merit and current relevance of different analytical and semi-analytical methods to be used in the fields of astrodynamics and celestial mechanics. Additionally, the author also hopes to offer an outcome of diverse interesting ideas and methods to be explored in future investigations in these research fields / Na atualidade, a despeito do desenvolvimento tecnológico experimentado pela ciência em geral, algo especialmente evidenciado por poderosas máquinas computacionais disponíveis, os métodos analíticos e semianalíticos para o estudo de diferentes problemas espaciais ainda são de grande importância nos campos de astrodinâmica e mecânica celeste. Desde a compreensão física do movimento de corpos celestes até ao planejamento e projeto de missões espaciais, o uso de modelos matemáticos para lidar com um grande número de problemas contemporâneos desempenha um papel fundamental no progresso do conhecimento humano. Neste contexto, a presente tese apresenta o uso de diferentes técnicas matemáticas para lidar com diversos e atuais problemas em astrodinâmica e mecânica celeste. Os estudos desenvolvidos ao longo deste trabalho são aplicáveis à ambas as áreas. Os tópicos estudados são os seguintes: (1) O desenvolvimento de potenciais perturbadores usando o processo de dupla média, de forma a serem incluídos nas equações planetárias de Lagrange que são integradas numericamente para estudar características de órbitas ao redor de Mercúrio e da lua galileana Calisto; (2) A utilização de diferentes integrais de perturbação, técnicas para identificar e mapear diferentes perturbações presentes em um sistema planetário, com foco na análise de sistemas de planetas gigantes com suas luas massivas; (3) A utilização do conceito de hamiltoniana intermediária e o uso de uma transformação canônica chamada eliminação da paralaxe, ambos para lidar com sistemas binários no contexto da dinâmica roto-orbital, essa sendo uma aproximação do problema completo de dois corpos; (3) Uma análise atualizada de equações variacionais de Gauss para o estudo de órbitas quasi-satélite ao redor da lua marciana Fobos e com predições analíticas realizadas após serem obtidas equações de movimento linearizadas e com média. Portanto, esta tese pretende não somente prover importantes análises e resultados para cada problema específico com os quais a mesma lida ao longo de suas páginas, mas também procura destacar o mérito e relevância atual de diferentes métodos analíticos e semianalíticos a serem utilizados nos campos de astrodinâmica e mecânica celeste. Adicionalmente, o autor também espera oferecer um produto de variadas ideias e métodos a serem explorados em futuras investigações nesses campos de pesquisa / 2013/26652-4 / 2015/18881-9

Submitted by Daniel Chada (danielc2112@gmail.com) on 2017-01-10T13:25:02Z No. of bitstreams: 1 chada.phd.2017.01.09.pdf: 5177057 bytes, checksum: a6174d9f2ba0b373776e750def2a23aa (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2017-01-12T14:03:51Z (GMT) No. of bitstreams: 1 chada.phd.2017.01.09.pdf: 5177057 bytes, checksum: a6174d9f2ba0b373776e750def2a23aa (MD5) / Made available in DSpace on 2017-01-23T11:48:10Z (GMT). No. of bitstreams: 1 chada.phd.2017.01.09.pdf: 5177057 bytes, checksum: a6174d9f2ba0b373776e750def2a23aa (MD5) Previous issue date: 2016-12-08 / Este trabalho consiste em três contribuições independentes do âmbito da modelagem cognitiva ao campo de management science. O primeiro aborda Experience Recognition, uma teoria inicialmente introduzida por Linhares e Freitas [91]. Aqui ela é estendida e delineada, além de se discutir suas contribuições para a ciência cognitiva e management science. A segunda contribuição introduz a framework cognitiva chamada Rotational Sparse Distributed Memory, e fornece uma aplicação-exemplo de suas características como substrato para um fortemente relevante campo da management science: redes semânticas. A contribuição final aplica Rotational Sparse Distributed Memory para a modelagem de motifs de rede, flexibilidade dinâmica e organização hierárquica, três resultados de forte impacto na literatura recente de neurociência. A relevância de uma abordagem baseada na modelagem neurocientífica para a decision science é discutida. / This work is comprised of three independent contributions from the realm of cognitive modeling to management science. The first addresses Experience Recognition, a theory first introduced by Linhares and Freitas [91]. Here it is extended and better defined, and also its contribution to cognitive science and management science are discussed. The second contribution introduces a cognitive framework called Rotational Sparse Distributed Memory, and provides a sample application of its characteristics as a substrate for a highly relevant subject in management science: semantic networks. The final contribution applies Rotational Sparse Distributed Memory to modeling network motifs, dynamic flexibility and hierarchical organization, all highly impactful results in recent neuroscience literature. The relevance of a neuroscientific modeling approach towards a cognitive view of decision science are discussed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this research was to evaluate of three grazing systems (GS) with Elephant grass (EG) + Italian ryegrass (IR) + spontaneous growing species (SGS); EG + IR + SGS + Forage peanut (FP); and EG + IR + SGS + Red clover (RC), in order to use the area in rotational grazing during all agricultural year. EG was planted in rows with a distance of 4 m each one of them. In the cool-season, IR was sowed between rows of EG; RC was sowed and the FP who has found established since 2006 was preserved on respectively GS. Experimental design was completely randomized with three treatments (GS), two replicates (paddocks) and independent evaluations (grazing cycles). For evaluation, were used lactating Holstein cows receiving 1% of BW day-1 feed supplement concentrate. The pre and post forage mass parameters, botanical and structural composition, forage production and stocking rate were evaluated. Samples were collected by the handplucking method to analyze the organic matter, mineral matter, crude protein (CP), neutral detergent fiber (NDF), in situ organic matter digestibility (ISOMD), in situ dry matter digestibility (ISDMD) of forage. Eight grazing cycle were performed during the experimental period (357 days). The values of forage production and stocking rate were 15.03, 16.33, 17.03 t ha-1 and 3.57, 3.52 and 3.65 animal unit ha-1, respectively grazing systems. Grazing systems involving grasses and forage legumes in different cycles provide use of the area during the agricultural year in rotational grazing with dairy cattle. SGS increased significantly (P≤0.05) over in GS without forage legume. Higher value of CP, ISOMD and lower of NDF for GS mixed with forage legumes. Considering the herbage mass, stocking rate and nutritive value, the pastures mixed to forage legumes showed better performance. / O objetivo desta pesquisa foi avaliar três sistemas forrageiros (SF) com capim elefante (CE) + azevém (AZ) + espécies de crescimento espontâneo (ECE); CE + AZ + ECE + amendoim forrageiro (AM); e CE + AZ + ECE + trevo vermelho (TV), com o intuito de utilização da área em pastejo rotativo durante todo o ano agrícola. O CE foi estabelecido em linhas afastadas a cada 4 m. No período hibernal fez-se o estabelecimento do AZ entre as linhas do CE; o TV foi semeado e o AM que já se encontrava estabelecido desde 2006, foi preservado, considerando os respectivos tratamentos. O delineamento experimental foi o inteiramente casualizado, com três tratamentos (SF), duas repetições (piquetes) e avaliações independentes (ciclos de pastejo). Para avaliação foram utilizadas vacas da raça Holandesa em lactação, que receberam suplementação alimentar com concentrado à razão de 1% do peso corporal dia-1. Foram avaliados parâmetros de massa de forragem pré e pós pastejo, composições botânica e estrutural, produção de forragem e taxa de lotação. Para analisar a matéria orgânica, matéria mineral, a fibra em detergente neutro (FDN), a proteína bruta (PB), a digestibilidade in situ da matéria seca (DISMS) e a digestibilidade in situ da matéria orgânica (DISMO) da forragem, foram coletadas amostras de pastejo simulado. Durante o período experimental (357 dias) foram efetuados oito ciclos de pastejo. Os valores de produção de forragem e de taxa de lotação foram de 15,03; 16,33; 17,03 t ha-1 e 3,57; 3,52 e 3,65 UA ha-1, respectivamente para os sistemas forrageiros. Sistemas forrageiros, envolvendo gramíneas e leguminosas de diferentes ciclos, proporcionam a utilização da área durante todo o ano agrícola em pastejo rotativo com bovinos leiteiros. Houve aumento significativo (P≤0,05) para ECE na pastagem sem leguminosa. Foram observados maiores valores de PB, DISMO e menores de FDN para os SF consorciados com leguminosas. Considerando a massa de forragem, a taxa de lotação e o valor nutritivo, as pastagens consorciadas com leguminosas forrageiras apresentaram melhor desempenho.

Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T19:36:49Z : No. of bitstreams: 1 silva_wl_me_jabo.pdf: 738598 bytes, checksum: 3bab2246fd6bc478a66e3929f5f28058 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A produção de forragem é influenciada pelas estratégias de manejo impostas a ela, desta maneira, as técnicas para identificação do melhor momento para início e término do pastejo, aliadas aos estudos das características morfogênicas e estruturais das plantas, tornam-se úteis para direcionamento do manejo, pois buscam auxiliar no melhor entendimento do crescimento vegetal, e por conseqüência, da produção forrageira. O experimento foi realizado no setor de Forragicultura, em área pertencente à FCAV da UNESP – Jaboticabal no período de dezembro de 2008 a abril de 2009, com o objetivo de avaliar o efeito de índices de área foliar residual (IAFr) sobre as características morfogênicas e estruturais, além do acúmulo de forragem em pastos de Cynodon spp cv Tifton-85 sob regime de lotação rotacionada com ovinos. Os tratamentos foram constituídos por três IAFr, 2,4, 1,6 e 0,8, mantidos por regime de lotação rotacionada com ovinos. O delineamento experimental utilizado foi o de blocos completos casualizados em arranjo de parcelas subdivididas no tempo com sete repetições, totalizando 21 unidades experimentais. Foram avaliadas nas condições de pré e pós-pastejo, as alturas do dossel, os IAF e a massa de forragem, além da taxa de acúmulo de forragem e as características morfogênicas e estruturais dos pastos. No pré e pós-pastejo as alturas médias e o IAF do dossel se comportaram de forma análoga, decrescendo com a diminuição dos IAFr. O maior valor de interceptação luminosa no pós-pastejo (68,19%), foi verificado para o IAFr 2,4 e o menor valor (35,57%) para o IAFr 0,8. A taxa de aparecimento de folhas foi maior para o dossel mantido sob IAFr 0,8 em função da sua menor taxa de alongamento de colmos (0,51 cm/perfilho.dia). Os pastos mantidos sob IAFr 0,8 apresentaram maior densidade populacional de perfilhos. A massa de forragem seca... / The production of forage is influenced by handling strategies imposed on the techniques to identify the best moment for the beginning and ending of grazing, linked to the studies of morphogenetic and structural characteristics of plants, become useful tools for the directing of management for they aim to aid the best understanding of vegetal growth, and as consequence, forage plants. The experiment was conducted at Setor de Forragicultura at Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, at UNESP – Jaboticabal from December 2008 to April 2009, and aimed to evaluate the effect of residual leaf area index (LAIr) about the morphogenical and structural characteristics, and forage accumulation in pastures of Cynodon spp cv Tifton-85 in a rotational stocking system with sheep. The treatments were constituted by three LAIr, 2,4, 1,6 e 0,8, maintained by rotational stocking with sheep. A complete randomized block design was used arranged in sub-divided parcels with seven replications, totaling 21 experimental units. They were evaluated in pre and post-grazing conditions, the height of the sward, LAI and forage mass, besides the accumulation of forage rate and the morphogenetic and structural characteristics. In the pre and post-grazing, the average height and the LAI of sward, decreasing with the diminishing of LAIr. The biggest value of light interception in post-grazing (68,19%), was verified by LAIr 2,4 and the smallest value (35,57%) for LAIr 0,8. The stem elongation rate (0,51 cm/tiller.day). The grazing maintained by LAIr 0,8 had higher tiller population density. The total dry forage mass was 27,1% superior for LAIr 2,4 regarding to LAIr 0,8 in pre-grazing conditions, being this total production, 72,0% was composed by stem fractions and dead material. The biggest rates of dry matter accumulation were observed with LAIr 2.4, in the second and third grazing cycles... (Complete abstract click electronic access below)

Made available in DSpace on 2016-08-17T18:39:34Z (GMT). No. of bitstreams: 1 3277.pdf: 7015864 bytes, checksum: 9834075e819d2bb62213cf25d21ce5e5 (MD5) Previous issue date: 2010-08-27 / Haemophilus influenzae type b (Hib) is a Gram negative bacterium responsible for causing meningitis worldwide. The capsular polysaccharide b, a polymer composed by repeating units of ribosyl-ribitol phosphate (PRP), is the major virulence factor and it is used in the formulation of the vaccine against this microorganism. Despite their high efficiency, the conjugated vaccine against Hib is a product of high production cost, which involves fermentation, purification and conjugation processes to obtain a final product within the specifications of the World Health Organization (WHO). The improvement of the culture medium and cultivation conditions can contribute to reduce the cost of this vaccine in order to facilitate its dissemination in developing countries. The main objective of this work was to identify culture conditions that result in higher production of capsular polysaccharide, helping to reduce costs in the steps of purification and conjugation. The experiments were carried out in shake flasks or in bioreactors with 7-13 liters of capacity. The temperature was maintained at 37 °C, pH controlled at 7.5 by adding NaOH 5M and the concentration of dissolved oxygen (CDO) maintained at 30% of air saturation. The specific flow rate of air ranged between 0.2 and 1 VVM. Samples were collected at regular time intervals to measure optical density (DO540nm), biomass concentration, capsular polysaccharide (PRP) production and concentrations of glucose and metabolites. Two possibilities for increasing polysaccharide production were studied: 1) different strategies of fed-batch cultivation consisting of: a) intermittent addition of glucose (FBIG), b) constant feeding (FBCF), c) exponential feeding (FBEF), e d) exponential feeding with cell recycle and perfusion (FBER + P); 2) improvement of culture media composition regarding the carbon/nitrogen ratio through the use of central composite rotational design (CCRD) methodology, having as independent variables: Soy Peptone (S), Yeast Extract (YE) and Glucose (G). Quality parameters were also evaluated to assess the molecular weight profile of the product (PRP) as well as morphological aspects of the microorganism. Economic analysis of different cultivation strategies was used to identify the more economically viable process. The results of the different cultivation strategies together with the outputs of the studied processes cost analysis showed that FBCF, with a cost of U.S.$ 425.50/g PRP and productivity of 88 mg/L.h, showed to be the best alternative among PRP production processes due to its lower cost with a good productivity. In the study of the culture media composition through the statistical analysis of the CCRD results showed that the best culture media composition (BCM) consisted of S 5 g/L; YE 5.5g /L and G of 15.25 g/L. DO540nm and PRP volumetric production values of 8.4 and 410 mg/L, respectively, were attained in validation experiments carried out in shake flasks at the BCM condition. For the bioreactor BCM validation experiment, biomass concentration of 3 g DW/L and polysaccharide production of 600 mg PRP/L were observed. Similar values were reached at validation runs performed in shake flasks and bioreactor for the central point CP condition, showing that both BCM and CP conditions belong to the optimum region. The analysis of quality parameters showed that the cultivation time influences strongly the size of the polysaccharide molecule. The longer the cultivation time, the lower molecular weight was found. The analysis by transmission electron microscopy (TEM) of H. influenzae cells revealed a predominance of round cells in the sixth hour of cultivation, whereas in the twelfth hour of cultivation the cells exhibited a more elongated morphology with the presence of cytoplasmic inclusions in the shape of granules, possibly due to the accumulation of some reserve material. Based on these results, the new composition of the culture medium resulted in an increased of cell growth and capsular polysaccharide production with half of the sources nitrogen (soybean peptone and yeast extract) concentrations, which reduces the production cost. The cultivations that resulted in higher production and productivity of polysaccharide were FBCF (1600 mg PRP/L and 88 mg PRP/(L.h)) and FBER+ P (1800 mg PRP/L and 129 mg PRP/(L.h)). The FBER+P reached 30% higher productivity of polysaccharide than the best result described in the literature (90 mg PRP/(L.h)). However, the FBCF cultivation was economically more viable. / Haemophilus influenzae tipo b (Hib) é uma bactéria Gram negativa responsável por causar meningite em todo o mundo. O polissacarídeo capsular b, um polímero composto por unidades repetidas de ribosil-ribitol-fosfato (PRP) e o principal fator de virulência, sendo utilizado na formulação da vacina contra este microrganismo. Apesar de sua elevada eficiência, a vacina conjugada contra Hib é um produto de alto custo de produção por envolver processos de fermentação, purificação e conjugação para obtenção de um produto final dentro das especificações da Organização Mundial da Saúde (OMS). O melhoramento do meio de cultura e das condições de cultivo pode contribuir para redução do custo desta vacina de forma a facilitar sua difusão nos países subdesenvolvidos. Assim, o principal objetivo deste trabalho foi identificar condições de cultivo que resultem em maior produção de polissacarídeo capsular, contribuindo para reduzir os custos nas etapas de purificação e conjugação. Os ensaios foram conduzidos em frascos agitados ou em biorreatores com 7 a 13 litros de capacidade nominal. A temperatura foi mantida em 37oC, o pH controlado em 7,5 através da adição de NaOH 5M e a concentração de oxigênio dissolvido (COD) mantida em 30 % da saturação do ar. A vazão especifica de ar variou entre 0,2 e 1 VVM. Amostras foram coletadas em intervalos regulares de tempo para mensurar densidade óptica (DO540nm), concentração celular, produção de polissacarídeo capsular (PRP) e concentrações de glicose e metabolitos. Duas possibilidades para aumentar a produção de polissacarídeo foram estudadas: 1) diferentes estratégias de cultivo descontinuo alimentado consistindo por: a) adição intermitente de glicose (CDAIG), b) vazão constante (CDAVC), c) vazão exponencial (CDAVE), e d) reciclo de células seguido de perfusão (CDAVE+P)); e 2) o melhoramento da composição do meio de cultura quanto à relação carbono/nitrogênio através do uso da metodologia de delineamento composto central rotacional (DCCR), tendo como variáveis independentes: Peptona de Soja (S), Extrato de Levedura (EL) e Glicose (G). Parâmetros de qualidade também foram avaliados para verificar o perfil da massa molecular do produto (PRP) e os aspectos morfológicos do microrganismo. Os resultados das diferentes estratégias de cultivo juntamente com os resultados da analise econômica do custo dos processos estudados mostraram que o CDAVC, com custo de US$ 425.50/g PRP por ano e produtividade de 88 mg/(L.h), demonstrou ser a melhor alternativa para o processo de produção de PRP por apresentar menor custo com boa produtividade. Já o estudo da composição do meio de cultura através da analise estatística dos resultados do DCCR mostraram que a melhor composição do meio de cultivo (MMC) consistia em S de 5 g/L, EL de 5,5 g/L e G de 15,25 g/L. Valores de DO540nm de 8,4 e de produção volumétrica de polissacarídeo de 410 mg PRP/L foram alcançados em experimentos de validação na condição MMC realizados em shaker. Para o ensaio de validação da condição MMC em reator, a concentração de biomassa de 3,0 g MS/L e a produção de polissacarídeo capsular de 600 mg PRP/L foram observadas. Valores semelhantes foram obtidos em experimentos de validação realizados em shaker e biorreator na condição CPC, mostrando que tanto a condição CPC como a MMC pertencem a região de ótimo. A analise dos parâmetros de qualidade mostrou que o tempo de cultivo influencia fortemente no tamanho da molécula do polissacarídeo, sendo que quanto maior o tempo de cultivo, menor a sua massa molecular. A analise por microscopia eletrônica de transmissão (MET) das células de H. influenzae mostrou a predominância de células com morfologia arredondada na sexta hora de cultivo, enquanto que, na décima segunda hora de cultivo, as células apresentaram morfologia mais alongada e exibiram a presença de inclusões citoplasmáticas na forma de grânulos, possivelmente devido ao acumulo de algum material de reserva. Diante dos resultados obtidos, a nova composição de meio resultou em maior crescimento celular e produção de polissacarídeo capsular, com metade das concentrações das fontes de nitrogênio (peptona de soja e extrato de levedura), o que reduz o custo de produção. Os cultivos que resultaram em maior produção e produtividade foram o CDAVC (1600 mg PRP/L e 88 mg PRP/L.h) e o CDAVE+P (1800 mg PRP/L e 129 mg PRP/L.h), sendo que este ultimo (CDAVE+P) atingiu produtividade 30 % maior que o melhor resultado ate então descrito na literatura (90 mg PRP/L.h). No entanto, o cultivo CDAVC apresentou maior viabilidade do ponto de vista econômico e de execução e passível de escalonamento.

Made available in DSpace on 2014-10-09T12:42:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:52Z (GMT). No. of bitstreams: 1 05403.pdf: 3608647 bytes, checksum: 066e3f6af2ef001c7431582e2ce35791 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:96/01220-7

The use of computational systems to solve engineering problems is increasingly present practical in the design offices. The Finite Element Method is one of the numerical techniques used in many of these systems, like the DOOLINES, a framework developed in objectoriented language, that allows a time domain dynamic analysis of the mooring lines and risers. In DOOLINES, until this work, the mooring lines and risers were discretized in onedimensional finite elements using a simplified formulation with six degrees of freedom (translational) element, with the consideration of only the axial and bending stiffness, when desirable, being this indirectly. This work incorporates into the DOOLINES class structure a new complete formulation element type that uses the co-rotational theory, with twelve degrees of freedom (translational and rotational) element, able to represent the axial, bending and torsional stiffness. The lumped-mass matrix is used in both formulations. This paper makes a comparative study of these elements about the quality of the response and the time required for simulation. / O uso de sistemas computacionais para resolução de problemas de engenharia é prática cada vez mais presente nos escritórios de projeto. O Método dos Elementos Finitos é uma das técnicas numéricas utilizadas em muitos desses sistemas, a exemplo do DOOLINES, um framework desenvolvido em linguagem orientada a objetos, que possibilita a análise dinâmica, no domínio do tempo, de linhas de ancoragem e risers. No DOOLINES, até então, as linhas de ancoragem e os risers eram discretizados em elementos finitos unidimensionais que utilizam uma formulação simplificada com seis graus de liberdade (translacionais) por elemento, com a consideração apenas das rigidezes axial e à flexão, quando desejável, sendo essa de maneira indireta. Neste trabalho, incorpora-se à estrutura de classes do DOOLINES um novo tipo de elemento com formulação completa de viga que utiliza a teoria corrotacional, com doze graus de liberdade (translacionais e rotacionais) por elemento, capaz de representar diretamente as rigidezes axial, à flexão e à torção. Em ambas as formulações considera-se a matriz de massa concentrada, onde se faz um estudo comparativo desses elementos no que se referem à qualidade da resposta e ao tempo de processamento necessário para simulação.