Foram conduzidos dois experimentos em casa-de-vegetação com o Panicum maximum cv. Mombaça cultivado em solução nutritiva, tendo sílica como substrato. Um experimento envolveu oito doses de potássio (0; 9,75; 39; 78; 156; 234; 312 e 468 mg L-1) e o outro oito doses de magnésio ( 0; 1,2; 3,6; 12; 24; 36; 48 e 60 mg L-1), sendo ambos conduzidos no período de janeiro a março de cada ano. O objetivo foi o de estudar o efeito das doses de potássio e magnésio na produção de massa seca, no número de perfilhos, na área foliar, no teor de clorofila estimado através da leitura SPAD, na concentração e acúmulo destes nutrientes nos componentes da planta e na determinação do nível crítico. O delineamento estatístico foi de blocos completos ao acaso, com quatro repetições. Observou-se efeito significativo e positivo das doses de potássio na produção de massa seca da parte aérea e das raízes, expressado por regressão quadrática e também na área foliar, representada por efeito linear. As doses de potássio afetaram significativamente o número de perfilhos, porém não influenciaram no teor de clorofila da lâmina foliar. A concentração de potássio nas folhas emergentes, nas lâminas de folhas recém-expandidas, nas lâminas de folhas maduras, nos colmos mais bainhas e nas raízes aumentou significativamente com o incremento de potássio na solução nutritiva. O maior e menor acúmulo de potássio na massa seca da parte aérea foram observados nos colmos mais bainhas e nas lâminas de folhas maduras, respectivamente. Observou-se efeito significativo positivo das doses de magnésio na produção de massa seca da parte aérea e das raízes, na área foliar e na estimativa do teor de clorofila, sendo representados por regressões quadráticas e lineares em função da variável estudada. As doses de magnésio aumentaram o número de perfilhos até a dose de 48 mg L-1. A concentração de magnésio nas folhas emergentes, nas lâminas de folhas recém-expandidas, lâminas de folhas maduras, nos colmos mais bainhas e nas raízes aumentou significativamente com o incremento de magnésio na solução nutritiva até a máxima dose estudada. O maior e menor acúmulo de magnésio na massa seca da parte aérea foram constatados nos colmos mais bainhas e nas lâminas de folhas emergentes, respectivamente. As lâminas de folhas recém-expandidas foram consideradas indicadoras para a avaliação do estado nutricional do capim-Mombaça associadas ao nível crítico de potássio entre 15,4 e 17,3 g kg-1 de massa seca e de magnésio de 4,2 g kg-1. / Two experiments were carried out in greenhouse conditions with Panicum maximum cv. Mombaça grown in nutrient solution, using ground quartz as substrate. One experiment had eight potassium rates (0; 9.75; 39; 78; 156; 234; 312 and 468 mg L-1) and another had eight magnesium rates (0; 1.2; 3.6; 12; 24; 36; 48 and 60 mg L-1) and were performed from January to March in each year. The objective was to evaluate the effects of potassium and magnesium rates on dry matter yield, tiller number, leaf area, chlorophyll concentration in the leaves throught SPAD readings, accumulation and concentration of each nutrient in plant components, and to estabilish parameters to determine the critical level of these two nutrients. In each experiment a complete randomized block design was used, with four replications. There was a positive effect of potassium rates in the dry matter yield of plant tops and roots, that fitted on quadratic models and in the leaf area expressed by linear models. Potassium rates affected the tiller number, but did not influence the estimated chlorophyll concentration in leaves. Potassium concentration in the emerging leaves, lamina of recently expanded leaves, lamina of mature leaves, stems plus sheaths and roots increased with potassium increasing in the nutrient solution. The highest and lowest potassium accumulation in the dry matter of plant tops were observed in stems plus sheaths and lamina of mature leaves, respectively. A positive effect of magnesium rates was observed in the dry matter of plant tops and root, in leaf area, in chlorophyll concentration, and they fitted in quadratic and linear models according to the studied variable. Magnesium rates in solution increased the tiller number up to 48 mg L-1. The concentration of magnesium in the emerging leaves, lamina of recently expanded leaves, lamina of mature leaves, stems plus sheaths and roots increased with magnesium solution from 0 to 60 mg L-1. The highest and lowest accumulation of magnesium in the dry matter of plant tops were observed in the stems plus sheaths and emerging leaves, respectively. The lamina of recently expanded leaves showed to be suitable for the evaluation of the nutricional status in potassium and magnesium of the Mombaça grass and the critical level were 15.4 and 17.3 g kg-1 for potassium and 4.2 g kg-1 for magnesium.

Lau Chui Pik. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 104-122). / Abstracts in English and Chinese. / Chapter Chapter 1 --- --- Introduction --- p.1 / Chapter 1.1 --- Importance of sinoatrial node in heart functions --- p.3 / Chapter 1.2 --- The importance of Adenosine 5'-triphosphate (ATP) --- p.5 / "ATP as a neurotransmitter, cotransmitter and neuromodulator" --- p.5 / Role of ATP in the heart --- p.7 / Chapter 1.3 --- Importance of delayed rectifier potassium channels (Ik) in the heart --- p.9 / Delayed rectifier potassium channel --- p.10 / Properties of Ik channels in the sinoatrial nodal (SAN)cells --- p.11 / Importance of Ik on heart function --- p.14 / Chapter 1.4 --- Drug/hormone/neurotransmitter modulation of Ik --- p.15 / Drugs modulations of Ik --- p.15 / Hormones/neurotransmitters modulations of Ik --- p.18 / Chapter 1.5 --- Problems encountered in using extracellular ATP on experiments --- p.23 / Chapter 1.6 --- Classification of P2-purinergic receptors --- p.24 / Major nucleotide receptors --- p.24 / p2X receptors --- p.26 / p2Y receptors --- p.28 / 1.7Objectives of the experiment --- p.30 / Chapter Chapter 2 --- --- Materials & Methods --- p.31 / Chapter 2.1 --- Materials --- p.32 / Chapter 2.1.1 --- Solutions --- p.32 / Chapter 2.1.2 --- Enzymes --- p.34 / Chapter 2.1.3 --- Drugs --- p.34 / Chapter 2.2 --- Methods --- p.35 / Chapter 2.2.1 --- Isolation of guinea pig SAN cells --- p.35 / Chapter 2.2.2 --- Identification of SAN region --- p.36 / Chapter 2.2.3 --- Obtaining of single SAN cells --- p.38 / Chapter 2.2.4 --- Preparation of micro-pipettes --- p.40 / Chapter 2.2.5 --- The Patch Clamp Technique --- p.40 / Recording configurations --- p.41 / Electrical recordings --- p.44 / Formation of gigaseal on cell membrane and the development of whole-cell configuration --- p.45 / The changing of bathing solution and addition of drugs --- p.46 / The voltage clamp protocol --- p.47 / Data acquisition and analysis --- p.48 / Statistics --- p.48 / Chapter Chapter 3 --- --- Results --- p.49 / Chapter 3.1 --- The modulatory effect of different concentrations of [ATP]0 on IKs in guinea pig SAN cells --- p.50 / Chapter 3.1.1 --- Characterization of IKs currents --- p.50 / Chapter 3.1.2 --- Stimulatory effect of extracellular A TP on IKs current --- p.51 / Chapter 3.1.3 --- Current-Voltage relationship of ATP on IKs current --- p.57 / Chapter 3.1.4 --- Percentage increase of IKs current in the presence of different [ATP] o --- p.63 / Chapter 3.2 --- Investigation on whether the enhancement effect on IKs is due to ATP or its metabolite adenosine --- p.71 / Chapter 3.2.1 --- Effect of 100 μMATP-γS and adenosine on IKs --- p.71 / Chapter 3.2.2 --- Percentage increase of IKs in the presence of adenosine and ATP-γS --- p.76 / Chapter 3.3 --- Investigation on whether or not G-protein signalling pathway involved in ATP-mediated response on SAN IKs --- p.80 / Chapter 3.3.1 --- Effects of GTP-γS alone on IKs --- p.80 / Chapter 3.3.2 --- Effect of 100 μM ATP in the presence of GTP-yS on IKs --- p.83 / Chapter Chapter 4 --- --- Discussion --- p.86 / Chapter 4.1 --- The modulatory effect of different concentrations of [ATP]0 on IKs in guinea pig SAN cells --- p.87 / Chapter 4.2 --- Investigation on whether the enhancement effect on IKs is due to ATP or its metabolite adenosine --- p.92 / Chapter 4.3 --- Investigation on whether or not G-protein signalling pathway involved in ATP-mediated response on SAN IKs --- p.97 / Chapter 4.4 --- Limitations of this study --- p.102 / Chapter 4.5 --- Future studies --- p.102 / Chapter Chapter 5 --- --- References --- p.104

Orientador: Adalton Mazetti Fernades / Coorientador: Pablo Forlan Vargas / Banca: Roberto Lyra Villas Bôas / Banca: Fábio Rafael Echer / Resumo: Para a maioria das hortaliças que produzem raízes tuberosas, o potássio (K) é o nutriente mineral exigido em maior quantidade. Entretanto, a aplicação de doses elevadas desse nutriente pode prejudicar o desenvolvimento das plantas, devido ao aumento da concentração salina ou mesmo decorrer em grandes perdas por lixiviação, especialmente em solos arenosos. Desta forma, o objetivo deste trabalho foi avaliar o crescimento e a produtividade da batata-doce submetida a doses e formas de parcelamento da adubação potássica em solos com diferentes teores iniciais de potássio (K). Foram conduzidos quatro experimentos em áreas com diferentes disponibilidades iniciais de K no solo (baixa = 0,7 mmolc dm-3; média = 1,4 e 1,5 mmolc dm-3 e alta = 3 mmolc dm-3) entre os anos de 2016 e 2018. O delineamento experimental utilizado foi o de blocos ao acaso, no esquema fatorial 3x4+1. Os tratamentos foram representados por três doses de K2O (60, 120 e 240 kg ha-1) combinadas com quatro formas de parcelamento (1 = 100% no plantio; 2 = 1/2 no plantio + 1/2 aos 40 dias após o plantio (DAP), 3 = 1/2 no plantio + 1/2 aos 90 DAP; 4 = 1/3 no plantio + 1/3 aos 40 DAP + 1/3 aos 90 DAP), além da testemunha sem K. O crescimento das plantas, em termos de biomassa produzida, aumenta em solos com baixo e médio teor inicial de K até as doses de 145 e 115 kg ha-1 de K2O, respectivamente. Em solos com alto teor inicial de K (≥ 3,0 mmolc dm-3), a adubação potássica não contribuiu para o acúmulo de matéria seca da p... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Among the majority of tuberous roots vegetables, potassium (K) is the most required mineral nutrient. However, the application of high rates of this nutrient may harm the plants development, due to the increase in saline concentration or even in large losses by leaching, especially in sandy soils. Thus, the purpose of this work was to evaluate the growth and yield of sweet potato submitted to rates and forms of K split application in soils with different K concentration. Four experiments were carried out in areas with different initial K availability in the soil (low = 0.7 mmolc dm-3, medium = 1.4 and 1.5 mmolc dm-3 and high = 3 mmolc dm-3) between 2016 and 2018. The experimental design was a randomized block design in the 3x4 + 1 factorial scheme. The treatments were represented by three doses of K2O (60, 120 and 240 kg ha-1) combined with four forms of plotting (1 = 100% at planting, 2 = 1/2 at planting + 1/2 at 40 days after planting (DAP), 3 = 1/2 at planting + 1/2 at 90 DAP, 4 = 1/3 at planting + 1/3 at 40 DAP + 1/3 at 90 DAP), in addition to the control without K. In terms of biomass produced, the plant growth increases in soils with low and medium initial K concentration up to 145 and 115 kg ha-1 of K2O, respectively. In soils with a high initial concentration of K (≥ 3.0 mmolc dm-3), K fertilization did not contribute to the accumulation of dry matter of the plant, but reduces the biomass accumulation in the tuberous roots. In soil with low initial K concentration, the commercial yield increases up to 171 kg ha-1 of K2O, and in soils with a medium initial K concentration, the increase in commercial yield reaches rates between 106 and 111 kg ha-1 of K2O. However, under high initial availability of K, the commercial yield reduces with the potassium fertilization until the rate of 60 kg ha-1 of K2O. The split application of K (planting + 40 + 90DAP) was shown to be more efficient in increasing ... / Mestre

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibligraphy: leaves 222-228. / by Paul Joseph Lemaire. / Ph.D.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1976. / Vita. / Bibliography: leaves 231-251. / Sc.D.

No Brasil, os sistemas de produção em ruminantes são principalmente a base do fornecimento de forragens cultivadas em grandes, medianas ou pequenas extensões do território nacional. A maior parte destas pastagens estão em um avançado estado de degradação por causa de um mal aproveitamento das vantagens que oferecem as gramíneas utilizadas nestes sistemas de produção. Um dos motivos pelos quais muitos estes sistemas ainda não são sustentáveis, é o mal uso ou não uso de suplementos no solo, levando o esgotamento de recursos em el solo muy importantes para o bom desenvolvimento de uma gramínea como o é o nitrogênio e o potássio. Como consequência disto, o desempenho animal, fator crítico nos sistemas de produção pecuário são baixos e o rendimento econômico faz que a empresa produtora de carne e leite bovino não seja rentável. Objetiva-se com este estudo avaliar o efeito a eficiência biológica de doses crescentes de adubação em pastagens de capim-marandu e capimmombaça durante os períodos de verão e outono com 3 tratamentos, e duas repetições. Foram 3 as doses de adubação avaliadas: 1) 50 kg N/ha + 50 kg K2O/ha; 2) 300 kg N/ha + 300 kg K2O/ha e 3) 600 kg N/ha + 600 kg K2O/ha, sobre os seguintes parâmetros: 1) massa de forragem produzida em cada um dos tratamentos no pré-pastejo; 2) Composição morfológica; 3) taxa de lotação; 4) frequência de pastejo; 5) composição químico-bromatológica. Foram utilizados 6 piquetes, cada um de 2 ha (3 de variedade Marandu e 3 de variedade Mombaça), nos quais foram coletadas as informações do trabalho de campo. Adicionalmente, dois piquetes com as mesmas dimensões, cada um, com uma das variedades de capim estudadas foram usados como área de reserva. Todos os piquetes foram divididos em 6 partes iguais e contaram com uma área de lazer de 15x30 metros. 181 novilhas foram utilizadas como agentes desfoliadores em ciclos de pastejo de 5 dias de ocupação e 25 de descanso para o campi-marandu e 7 dias de ocupação e 35 de descanso para o campi-mombaça. No período da seca foi testado o desempenho de 103 novilhas entre prenhes e vazias suplementadas com dietas a base de cana-de açúcar e 4 fontes de proteína (farelo de soja, farelo de soja + uréia, uréia e uréia de liberação lenta). A taxa de lotação tive um efeito linear positivo às doses de N e KCl avaliadas. A qualidade do capim foi pouco influenciada pelos tratamentos. Todos os suplementos usados na época da seca permitiram manter o peso médio e obter um ganho de peso adicional. O uso de adubos nitrogendos e potássicos permite aumentar a eficiência do uso da terra permitindo disponibilizar áreas dedicadas à pecuária para outro tipo de atividades no agronegócio. / In Brazil the ruminant production systems are mainly based on the offer of pastures cultivated in large, medium or small areas of the country. Most of the prairies in these production systems are in an advanced state of degradation due to misuse of the gramineae advantages making them unsustainable. The misuse or non-use of soil supplements leads to the depletion of resources such as nitrogen and potassium highly important for the proper development of grass. As a consequence the animal performance, a critical factor in livestock production systems is low, causing a negative impact on economic efficiency of the meat and milk production enterprise making it not profitable. The aim of this study was to evaluate the effect and biological efficiency of increasing doses of fertilizers on Marandu and Mombaça pasture prairies during summer and autumn periods with three treatments in two repetitions. With three fertilizer doses evaluated: 1) 50 Kg of N/ha + 50 Kg of K2O/ha; 2) 300 Kg of N/ha + 300 Kg of K2O/ha and 3) 600 Kg of N/ha + 600 Kg of K2O/ha; on the following parameters: 1) mass of forage produced in each of the treatments on the pre-grazing, 2) morphological composition, 3) livestock rate, 4) frequency of grazing, 5) chemical and bromatological composition. 6 paddocks were used, each one of 2 ha (3 with Marandu variety and 3 Mombaça variety) were field work information was collected. Additionally, two fields with the same dimensions mentioned above, each one with the grass varieties tested were used as a reserve area. All paddocks were divided into 6 equal parts and counted with a rest area of 15 x 30 meters. 181 heifers were used to consume the accumulated pasture in grazing cycles, 5 days of occupation and 25 days off in Marandu pasture prairies and 7 days of occupation and 35 days off for Mombaça pasture prairies. In the drought period the performance of 103 pregnant heifers both pregnant and non-pregnant was evaluated, they were fed with diets supplemented with sugar cane and 4 protein sources (soybean meal; soybean meal+ urea; urea; and slow release urea).Lifestock rate had a positive linear effect on increasing doses of the N and KCl evaluated.. Pasture quality was poorly influenced by the treatments. All supplements used in the dry season allowed maintaining weight and additional weight gain. The use of nitrogen and potassium fertilizers allowed the increase of efficiency of soil and to use areas dedicated to livestock to other activities in the agribusiness.

O manjericão é uma das ervas mais populares e úteis na culinária, devido ao seu aroma delicado e à sua fragrância. As principais formas de utilização são o manjericão fresco, seco ou o óleo essencial, sendo esta última a forma que apresenta maior valor agregado. As necessidades hídricas e a adubação potássica são uns fatores importantes nos parâmetros de produtividade de biomassa e óleo essencial de manjericão. O objetivo deste trabalho foi avaliar o efeito de diferentes lâminas de irrigação e doses de potássio sobre a produção de biomassa e óleo essencial de manjericão variedade \"Lampião\", originária da coleção do IAC (Instituto Agronômico de Campinas), em três períodos de colheita. O experimento foi instalado sob um delineamento experimental e em esquema fatorial 4 x 4, em blocos aleatorizados com parcelas subdivididas, constando de quatro lâminas de irrigação necessária para elevar a água do solo à capacidade de campo: L1 - 100% CAD, L2 - 75% CAD, L3 - 30% CAD, L4 - sem irrigação e quatro doses de potássio; D1 - 0 kg de K2O ha-1, D2 - 50 kg de K2O ha-1, D3 - 100 kg de K2O ha-1 e D4 - 200 kg de K2O ha-1. A área experimental foi constituída de 48 parcelas, cada parcela com 2,5 m de comprimento e 2,0 m de largura. O sistema de irrigação utilizado foi o gotejamento, adotando o manejo de irrigação com estimativa da umidade do solo por meio de dados da sonda de capacitância, modelo Diviner 2000®. Foi quantificado o consumo hídrico do manjericão e estimou-se o coeficiente de cultura (Kc) relacionando-o à soma de graus dia (GD) e ao índice de cobertura vegetal (IC). A evapotranspiração da cultura (ETc), em mm d-1 foi determinada com o auxílio de três lisímetros de drenagem, fazendo-se o balanço de entradas e saídas de água. A evapotranspiração de referência (ETo), em mm d-1 foi estimada pelo método Penman-Monteith, preconizado pela FAO-56, para obter o Kc. Foram avaliadas as variáveis de produção de mudas, de crescimento, produção de biomassa e rendimento de óleo essencial. O consumo hídrico da cultura foi de 71 mm, 103 mm e 187 mm, correspondendo aos valores médios de 1,03; 1,84 e 3,07 mm d-1 nos períodos de cultivos I, II e III, respectivamente. Observou-se variações nos valores de Kc decorrentes das condições climáticas e das fases fenológicas da cultura. Os valores máximos e mínimos dos Kc foram 0,37-0,23; 0,60-0,27; 1,00-0,38 e 1,15-0,82 para as fases fenológicas I, II, III e IV, respectivamente. A estimativa do Kc em função do GD e do IC foram significativas para a cultura nos três períodos de cultivos. O modelo da área, AF=10(0,92327 Aelipse), que utilizou a área da elipse (C L (?/4)), mostrou-se o mais adequado para a estimativa da área foliar do manjericão. As lâminas de irrigação e doses de potássio apresentaram incremento no rendimento de óleo essencial. Houve um maior acréscimo no rendimento de óleo essencial referente às lâminas de irrigação do que as doses de potássio. / Basil is one of the most popular and useful herbs in cooking due to its delicate aroma and fragrance. The main forms of using basil are fresh, dried or essential oil, being this last one the form with higher value added. The assessment of water requirement associated with potassium fertilization is an important factor in the productivity parameters of biomass and essential oil of basil. This study aimed to evaluate the effect of irrigation depths and potassium rates on biomass and essential oil of basil variety \"Lampião\" in three periods. The experiment was conducted in an experimental randomized block design with split plots consisting of four depths of irrigation needed to raise the water from the soil to field capacity: L1 - 100% FC, L2 - 75% FC, L3 - 30% FC, L4 - without irrigation and four potassium rates; D1 - 0 K2O kg ha-1, D2 - K2O 50 kg ha-1 D3 - 100 kg ha-1 K2O and D4 - 200 kg ha-1 K2O. The experimental area consisted of 48 plots, each plot with 2.5 m in length and 2.0 m wide, totaling 5.0 m2. The irrigation system used was dripping, adopting the irrigation management by estimating the soil moisture using data from capacitance probe, Diviner 2000 ® model. The water consumption of basil was quantified and the crop coefficient (Kc) was estimated relating it to the sum of degree days (DD) and the index of vegetation cover (IVC). Through three drainage lysimeters, being the crop evapotranspiration accounting (ETc) in mm d-1, held by the inputs and outputs of water, and the reference evapotranspiration (ETo) in mm d-1 estimated by Penman-Monteith method, recommended by the FAO-56. The variables analyzed were the variables of seedling production, growth, biomass production and essential oil yield. The crop water consumption was 70.91 mm, 103 mm and 187 mm, corresponding to an average value of 1.03; D 1.84 and 3.07 mm-1 crops during periods of I, II and III, respectively. It was observed variations in the values of Kc due to climate conditions and phenological stages. The maximum and minimum values of Kc were 0.37 to 0.23; 0.60 to 0.27; 1.00 to 0.38 and 1.15 to 0.82 for the phenological stages I, II, III and IV, respectively. The estimate of Kc as a function of DD and IVC were highly significant for culture in the three periods of crops. The AF=10(0,92327 Aelipse), which was used the area of the ellipse as (CL (?/4)), proved the most suitable for the estimation of basil leaf area index. The irrigation and potassium levels showed an increase in oil yield. There was a greater increase in oil yield related to irrigation than the potassium.

Plantações clonais de eucalipto no Brasil apresentam as maiores médias de produtividade de madeira entre os principais países produtores. Dentre os fatores responsáveis por este êxito, estão as corretas práticas de manejo, em que as fertilizações minerais constituem uma das principais. Apesar de apresentar boas condições climáticas e atributos físicos do solo favoráveis, as florestas plantadas no Brasil necessitam de fertilizações com macro e micronutrientes. Na maioria dos solos e plantações florestais, as respostas são maiores para P e K, mas acredita-se que, devido às sucessivas rotações de produção e às elevadas quantidades de N exportadas, respostas às fertilizações nitrogenadas serão comuns em futuras rotações de cultivo. O objetivo deste estudo foi identificar as doses de N, P e K e fontes de N adequadas e a resposta à aplicação de Ca em plantações clonais de eucalipto e suas interações com fatores edafoclimáticos. Não apenas os teores nutricionais no solo, mas também os materiais genéticos e as condições climáticas influenciaram as respostas às fertilizações minerais. Em solos com teores entre baixo e médio de matéria orgânica e textura arenosa, foram verificadas respostas em produção de madeira entre 4 e 47% aos 60 meses para a aplicação das maiores doses de N. A ureia apresentou resultados de produção volumétrica de madeira próximos à dose equivalente de nitrato de amônio. A fertilização fosfatada proporcionou ganhos de produtividade em solos com teores de P-resina até 5 mg dm-3. Os ganhos em produtividade diminuíram com a idade dos povoamentos e, entre os 48 e 60 meses após o plantio, ficaram entre 14 e 19 %. Não houve influência climática ou do material genético associadas à fertilização fosfatada. Contrastando ao N e P, as respostas à fertilização potássica aumentaram com a idade em três dos quatro sítios estudados. Os ganhos de produtividade com a aplicação da maior dose de K ficaram entre 2 e 99% nas avaliações realizadas aos 48 e 60 meses após o plantio. Apesar dos teores do nutriente no solo serem considerados muito baixos para todos os locais, as respostas foram diferentes. Em Paulistânia, local com as maiores produtividades, as respostas à aplicação de K foram próximas a zero. O menor déficit hídico neste sítio foi identificado como fator mais influente. Para os três macronutrientes primários, os teores foliares diminuíram com a idade, e mesmo na ausência de respostas eles estiveram abaixo de teores foliares adequados. Não houve resposta à aplicação de Ca. / Clonal eucalyptus plantations in Brazil have the highest average productivity of wood amongst the main producing countries. Among those responsible for this success are the correct management practices, in which mineral fertilizations are a major. Despite showing good weather and favorable physical attributes of the soil, planted forests in Brazil require fertilization with macro and micronutrients. In most of the soils and forest plantations, responses are higher for phosphorus and potassium, but it is believed that due to successive rotations of production and high amounts of N exported, responses to nitrogen fertilization will be common in future rotations of cultivation. The aim of this study was to identify appropriate doses of N, P and K in clonal eucalyptus plantations and their interactions with edaphoclimatic factors. This study found that not only the nutritional content of the soil, but also the genetic materials and climatic conditions influence responses to mineral fertilization. In soils with low to medium organic matter levels and coarse texture responses between 4 and 47% were observed at 60 months, for the application of higher doses of N. Urea showed productivity responses close to the equivalent dose of ammonium nitrate. The P fertilization led to gains in productivity in soils with levels of P-resin up to 5 mg dm-3. Productivity gains evaluated decreased with age of the stands, and between 48 and 60 months after planting, were between 14 and 19%. There was no climate or genetic material linked to phosphorus fertilization influence. In contrast to N and P, the responses to potassium fertilization increased within age in three of the four studied sites. Productivity gains from the implementation of higher dose of K were between 2 and 99% in the assessments at 48 and 60 months after planting. Although the levels in the soil are considered very low for all sites, the answers were different. In Paulistânia, location with the highest yields, responses to K were close to 0. The smaller water deficit in this site was identified as the most influential factor to the results. For the three primary macronutrients, it was found that these foliar concentrations decreased with age, and that even in the absence of answers they were below levels recommended foliar elsewhere. There was no response to the application of Ca.

Hui Fong Fong Liza. / Thesis submitted in: December 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 130-182). / Abstracts in English and Chinese. / Chapter I --- Title page --- p.I / Chapter II --- Thesis committee --- p.II / Chapter III --- Acknowledgements --- p.III / Chapter IV --- Abstract (Chinese version) --- p.IV / Chapter V --- Abstract (English version) --- p.VII / Chapter VI --- Table of contents --- p.X / Chapter VII --- List of figures --- p.XIV / Chapter VIII --- List of table --- p.XVIII / Chapter Chapter 1: --- General introduction --- p.1 / Chapter Chapter 2: --- Literature review --- p.5 / Chapter 2.1. --- Gill --- p.5 / Chapter 2.2. --- Chloride cells (Mitochondria-rich cells) --- p.6 / Chapter 2.2.1. --- Ion extrusion by fish in seawater --- p.9 / Chapter 2.2.2. --- Ion uptake by fish in hypo-osmotic condition --- p.12 / Chapter 2.3. --- Sparus sarba (Silver seabream) --- p.14 / Chapter 2.4. --- Sodium-potassium adenosinetriphosphatase (Na+-K+-ATPase) --- p.15 / Chapter 2.4.1. --- Na+-K+-ATPase α-subunit --- p.17 / Chapter 2.4.2. --- Na+-K+-ATPase β-subunit --- p.18 / Chapter 2.4.3. --- Regulation of Na+-K+-ATPase --- p.20 / Chapter 2.5. --- Hormones --- p.21 / Chapter 2.5.1. --- Growth hormone-prolactin family --- p.21 / Chapter 2.5.2. --- Structure of hormones --- p.22 / Chapter 2.5.2.1. --- Structure of growth hormone and prolactin in fish --- p.22 / Chapter 2.5.2.2. --- Structure of insulin-like growth factors in fish --- p.26 / Chapter 2.5.2.3. --- Structure of Cortisol in fish --- p.27 / Chapter 2.5.3. --- Regulation of hormones --- p.28 / Chapter 2.5.3.1. --- Regulation of growth hormone in fish --- p.28 / Chapter 2.5.3.2. --- Regulation of prolactin in fish --- p.32 / Chapter 2.5.3.3. --- Regulation of insulin-like growth factor-I in fish --- p.33 / Chapter 2.5.3.4. --- Regulation of Cortisol in fish --- p.33 / Chapter 2.5.4. --- Functions of hormones --- p.33 / Chapter 2.5.4.1. --- Functions of growth hormone in fish --- p.33 / Chapter 2.5.4.2. --- Functions of prolactin in fish --- p.39 / Chapter 2.5.4.3. --- Functions of insulin-like growth factor-I in fish --- p.44 / Chapter 2.5.4.4. --- Functions of Cortisol in fish --- p.45 / Chapter 2.5.4.5. --- "Combined effects of GH, IGF-I, PRL and Cortisol" --- p.49 / Chapter 2.6. --- Salinity effects on Na+-K+-ATPase expression --- p.52 / Chapter Chapter 3: --- In vitro effect of hormones on branchial Na+-K+- ATPase expression in marine teleost Sparus sarba --- p.58 / Chapter 3.1. --- Abstract --- p.58 / Chapter 3.2. --- Introduction --- p.60 / Chapter 3.3. --- Materials and methods --- p.62 / Chapter 3.3.1. --- Overall experimental design --- p.62 / Chapter 3.3.2. --- Fish preparation --- p.62 / Chapter 3.3.3. --- Tissue sampling --- p.62 / Chapter 3.3.4. --- RNA extraction and dot blot analysis --- p.63 / Chapter 3.3.5. --- Protein extraction --- p.65 / Chapter 3.3.6. --- Protein quantification --- p.65 / Chapter 3.3.7. --- Na+-K+-ATPase activity --- p.65 / Chapter 3.3.8. --- Protein gel electrophoresis and immunoblotting (Western blotting) --- p.66 / Chapter 3.3.9. --- Statistical analysis --- p.67 / Chapter 3.4. --- Results --- p.69 / Chapter 3.4.1. --- Dot blot analysis of Na+-K+-ATPase mRNA subunits --- p.69 / Chapter 3.4.2. --- Analysis of Na+-K+-ATPase protein α-subunit --- p.81 / Chapter 3.4.3. --- Analysis of Na+-K+-ATPase activity --- p.87 / Chapter 3.5. --- Discussion --- p.92 / Chapter 3.5.1. --- Effects of rbGH and rbIGF-I on Na+-K+-ATPase expression --- p.92 / Chapter 3.5.2. --- Effects of oPRL on Na+-K+-ATPase expression --- p.102 / Chapter 3.5.3 --- Effects of Cortisol on Na+-K+-ATPase expression --- p.104 / Chapter 3.6. --- Conclusion --- p.108 / Chapter Chapter 4: --- In vivo effect of salinity on branchial Na+-K+-ATPase expression in marine teleost Sparus sarba --- p.109 / Chapter 4.1. --- Abstract --- p.109 / Chapter 4.2. --- Introduction --- p.110 / Chapter 4.3. --- Materials and methods --- p.112 / Chapter 4.3.1. --- Overall experimental design --- p.112 / Chapter 4.3.2. --- Fish preparation --- p.112 / Chapter 4.3.3. --- Tissue sampling --- p.113 / Chapter 4.3.4. --- "RNA extraction, dot blot analysis, protein extraction, quantification, Na+-K+-ATPase activity, protein gel electrophoresis and immunoblotting (Western blotting)" --- p.113 / Chapter 4.3.5. --- Statistical analysis --- p.114 / Chapter 4.4. --- Results --- p.114 / Chapter 4.4.1. --- Dot blot analysis of Na+-K+-ATPase mRNA subunits --- p.114 / Chapter 4.4.2. --- Analysis of Na+-K+-ATPase protein a-subunit --- p.114 / Chapter 4.4.3. --- Analysis of Na+-K+-ATPase activity --- p.115 / Chapter 4.5. --- Discussion --- p.120 / Chapter 4.6. --- Conclusion --- p.125 / Chapter Chapter 5: --- General discussion and conclusion --- p.126 / References --- p.130