Thèses sur le sujet « Nutrient »
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Henderson, Courtney Francis Keith. « The Chemical and Biological Mechanisms of Nutrient Removal from Stormwater in Bioretention Systems ». Thesis, Griffith University, 2009. http://hdl.handle.net/10072/366977.
Texte intégralThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Engineering
Science, Environment, Engineering and Technology
Full Text
Cromwell, Diane. « Pancreatic beta-cell actions of nutrients and metabolizable nutrient ester derivatives ». Thesis, University of Ulster, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494335.
Texte intégralHeeley, Nicholas John. « Hypothalamic nutrient sensing ». Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271628.
Texte intégralFernandes, Adalton Mazetti [UNESP]. « Crescimento, produtividade, acúmulo e exportação de nutrientes em cultivares de batata (Solanum tuberosum L.) ». Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/86341.
Texte intégralConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A cultura da batata tem grande importância para o Brasil e para o Estado de São Paulo. Porém, apesar de sua importância, falta maiores informações sobre a fisiologia e nutrição mineral desta cultura, limitando a obtenção de elevadas produtividades, com alta qualidade e baixo custo de produção, já que as peculiaridades de cada cultivar podem fazer grande diferença no manejo. Além disso, as doses de fertilizantes normalmente utilizadas na cultura da batata são elevadas, o que gera grande impacto no custo de produção e riscos ambientais. Assim, para obtenção da máxima eficiência produtiva, faz-se necessário o conhecimento do desenvolvimento da planta e da absorção e acumulação de nutrientes nas diferentes fases de desenvolvimento. O objetivo deste trabalho foi avaliar o crescimento, acúmulo de nutrientes durante o ciclo, produtividade de tubérculos e exportação de nutrientes em cinco cultivares de batata. O delineamento experimental utilizado foi o de blocos casualizados, em esquema de parcela subdividida, com quatro repetições. As parcelas foram constituídas pelas cultivares (Ágata, Asterix, Atlantic, Markies e Mondial) e as subparcelas por épocas de coletas de plantas, que foram realizadas a cada 7 dias após a emergência até a colheita final. Cada parcela foi constituída por 10 linhas de 10 m de comprimento. Todas as cultivares tiveram crescimento lento até o início da fase de enchimento de tubérculos. Desta época até o final do ciclo ocorreu o desenvolvimento dos tubérculos, com a máxima taxa de acúmulo de MS concentrando-se no início dessa fase. A cultivar Mondial foi mais tardia em acumular MS, apresentando as maiores taxas de crescimento na fase final do ciclo.As cultivares Ágata, Atlantic e Markies apresentam crescimento semelhante durante todo o ciclo, porém...
The potato crop has great economical importance for Brazil and São Paulo State. However, despite its importance, it lacks more information about physiology and mineral nutrition of this crop, limiting to obtain high yield, high quality and low production cost, since the peculiarities of each cultivar can make difference in management. Furthermore, the fertilizers rates commonly used in potato crop are high, which has a strong impact on production costs and environmental risks. To get the maximum production efficiency, it is necessary to understand the development of the plant, uptake and accumulation of nutrients in different stages of the plant development. The objective of this study was to evaluate growth, nutrient accumulation, tubers yield and the nutrient exportation in five potato cultivars. The experimental design was the completely randomized block in split-plot with four replications. The plots treatments consisted of potato cultivars (Ágata, Asterix, Atlantic, Markies and Mondial) and subplots were established by harvest time of plants, were carried out every 7 day after emergence to last harvest. Each plot consisted of 10 lines of 10 m in length. All cultivars showed slow growth until the beginning of the tubers bulking stage. Since this time until the end of the cycle, occurred the tubers development, with maximum dry matter accumulation rate focusing in this initial stage. Mondial cultivar took longer time to accumulate dry matter, presenting the highest growth rates in the final stage of the cycle. Ágata, Atlantic... (Complete abstract click electronic access below)
Thornton, R. C. « Sediment-associated nutrients and their contribution to the nutrient loads of Devon catchments ». Thesis, University of Exeter, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354030.
Texte intégralNASCIMENTO, Sandra Maria do. « Distribuição, exportação e ciclagem de nutrientes minerais em Cupiúva (Tapirira guianensis Aubl.), em um fragmento manejado de mata atlântica no município de Goiana - PE ». Universidade Federal Rural de Pernambuco, 2006. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5114.
Texte intégralMade available in DSpace on 2016-07-28T16:39:44Z (GMT). No. of bitstreams: 1 Sandra Maria do Nascimento.pdf: 553060 bytes, checksum: af162526240a5bf78aa1ac5c4f3cbba7 (MD5) Previous issue date: 2006-05-31
The Atlantic rainforest is one of the richest biomasses of the planet in terms of biodiversity, but has been compromised by considerable anthropogenic action. The present study investigated a managed fragment of the Atlantic rainforest in the city of Goiana, PE, Brazil, on the Megaó farmland, with the aim of evaluating the distribution and exportation of mineral nutrients in Tapirira guianensis Aulb. (cupiúva), a perennial, pioneering halophyte species belonging to the family Anacardiaceae. Analysis of the mineral nutrients in the vegetal biomass and litter was carried out at the Mineral Nutrition of Plant Laboratory (Chemistry Department) and the Soil Chemistry Laboratory (Agronomy Department); soil analysis was carried out at the Soil Physics and Soil Fertility Laboratories (Agronomy Department) of the Rural Federal University of Pernambuco. Macronutrient (N, P, K, Ca, Mg, S) and micronutrient (Cu, Fe, Mn, Zn) determinations were performed on the leaves, branches, bark and trunk. Pre-dried samples were submitted to nitro-perchloric digestion, with the exception of N, for which sulfuric digestion was performed. Colorimetry was used for the analytic determination of P, whereas turbidimetry was used for S; K was assessed using the flame photometric technique, and the Ca, Mg, Cu, Fe, Mn and Zn contents were determined by the atomic absorption spectrophotometric method. N concentration was determined by the Kjeldahl method. Results were submitted to variance analysis and the averages were compared through the Tukey test at 5 % probability. The concentration of nutrients in the Tapirira guianensis Aulb. biomass obeyed the following order: leaves>bark>branches>trunk. The distribution of macronutrients in the leaves, bark and branch were distributed in N>Ca>Mg>K>S>P, and in the trunk in N>Ca>S>P>Mg>K. Micronutrients followed the distribution sequence for all arboreal components: Fe>Zn>Mn. The leaves presented a greater accumulation of nutrients, despite their biomass being smaller than the remaining components. Leaf maintenance is therefore important in the management area, thereby ensuring the cycling of nutrients through litter and the adequate maintenance of the management area. The total of exported nutrients was 71 % at the time of the cutting of the tree when the trunk, bark and branches are removed from the site, which could compromise the sustainability of the site.
A mata Atlântica é um dos biomas mais ricos em biodiversidade do planeta, diversidade esta que se encontra comprometida por causa da forte ação antrópica, que entre outros problemas, produz a degradação do solo. O presente trabalho teve como área de estudo um fragmento manejado de mata Atlântica no município de Goiana – PE, na fazenda Megaó. O objetivo foi avaliar a distribuição e exportação de nutrientes minerais em Tapirira guianensis Aulb. (cupiúva), espécie perenifólia, pioneira, e heliófita, pertencente à família Anacardiaceae. As análises dos nutrientes minerais na biomassa vegetal e na serrapilheira foram realizadas no Laboratório de Nutrição Mineral de Plantas (Departamento de Química) e no Laboratório de Química do Solo (Departamento de Agronomia), e as análises do solo foram realizadas nos Laboratórios de Física do solo e Fertilidade do Solo (Departamento de Agronomia), da Universidade Federal Rural de Pernambuco. As determinações dos macronutrientes (N, P, K, Ca, Mg, S) e micronutrientes (Cu, Fe, Mn, Zn), foram realizadas nas folhas, galhos, casca e fuste. As amostras pré-secas foram submetidas à digestão nitroperclórica, com exceção do N, onde foi feita a digestão sulfúrica. A determinação analítica de P se deu por colorimetria e S por turbidimetria; K, foi avaliado através da técnica de fotometria de chama e os teores de Ca, Mg, Cu, Fe, Mn e Zn foram determinados pelo método de espectrofotometria de absorção atômica. Os teores de N foram determinados pelo método de Kjeldahl. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5 % de probabilidade. A concentração de nutrientes na biomassa da cupiúva obedeceu a seguinte ordem folhas>casca>galhos>fuste. A distribuição de macronutrientes nas folhas, casca e galho foi distribuídos em N>Ca>Mg>K>S>P e no fuste foi N>Ca>S>P>Mg>K. Os micronutrientes seguiram a seqüência de distribuição para todos os componentes arbóreos Fe>Zn>Mn. As folhas apresentaram maior concentração de nutrientes, apesar de sua biomassa ser menor que os outros componentes, sendo assim importante sua manutenção na área de manejo, garantindo a ciclagem de nutrientes via serrapilheira e a boa manutenção da área de manejo. O total de nutrientes exportados no momento do corte da árvore, em que são retirados o fuste, a casca e os galhos do sítio, é de 71 %, o que representa uma grande perda no total de nutrientes da área de manejo, e pode comprometer a sustentabilidade do sítio.
Burdette, Sarah Beth. « Effects of excessive nitrogen deposition on foliar nutrient dynamics, nutrient concentrations, and nutrient ratios in a Central Appalachian hardwood forest ». Huntington, WV : [Marshall University Libraries], 2002. http://www.marshall.edu/etd/descript.asp?ref=78.
Texte intégralTitle from document title page. Document formatted into pages; contains x, 52 p. with maps and illustrations. Includes bibliographical references (p. 48-52).
Barthelemy, Hélène. « Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems ». Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-120191.
Texte intégralDiaz, Hector Luis. « COORDINATION OF NUTRIENT SENSING, NUTRIENT AVAILABILITY, AND CELL GROWTH IN RUMEN PROTOZOA ». The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345571314.
Texte intégralSatha, Ganarupan. « Nutrient Driven Topology Optimization ». Thesis, Linköpings universitet, Mekanik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70785.
Texte intégralTajuddin, Rosnida Binti. « Nutrient transport in ectomycorrhiza ». Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=210785.
Texte intégralBista, Deepesh R. « Effect of Climate Change on Nutrient Uptake and Nutrient-Uptake Proteins in Roots ». University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513286902000333.
Texte intégralFerreira, Francisco Jardelson. « Fertilization rose bushes based on nutrient balance in the soil - plant system ». Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17134.
Texte intégralRose is an economically important crop for the national and the international market and due to this fact generates income to the Ceara State. Rose is a demanding crop in relation to fertilizers, requiring knowledge of soil fertility, nutritional plant requirements and nutrients use efficiency to obtain adequate fertilization. Based on the nutritional balance through the use of mechanistic and empirical models, it is possible to develop a system to quantify the plant nutrients demands to achieve a given productivity. This paper aims to establish parameters of a fertilizer and lime recommendation system to rose crop, based on the plant nutritional balance. The experiment was conducted at the company Cearosa in SÃo Benedito - CE. Plants will be collected during five months and once a month, five rose plants from four varieties (Top Secret, Avalanche, Attache and Ambience) As contradictory Airlines plants Were grinded. Samples will be ground and nutrients content will be determined: N, P, K, Ca, Mg, S, B, Fe, Mn, e Zn. Every sampling plant time, were also soil samples collected at two depths (0-20 and 20-40 cm) In which they underwent fertility analysis. To estimate the fertilizer recommendation, the system was be subdivided into requirement subsystem (REQ), which includes the plant nutrients demands, considering the recovery efficiency of the nutrients to be applied and a rate to achieve the "sustainability" criteria and the supply subsystem (SUP) that comprises the soil nutrient supply. After determining the total REQ and SUP, held -if the nutritional balance, and if the result is positive (REQ> SUP), fertilizers application is recommended and if the result negative or zero (REQ ≤ SUP), fertilizers application is not recommended. The system estimated that there is excess nitrogen and phosphorus fertilization for all cultivars , however , there needs to be supplemental potassium fertilizer . The system estimated that the soil is able to meet the demand of plants for P and Fe for all cultivars , however , there must be supplementary nitrogen fertilizer , potassium . As for micronutrients , the system estimated that there is need for additional fertilizer for Zn in all rosebushes and Mn for the rosebushes "Top Secret " and " Avalnche " , however with very close recommendation the optimal dose , ie equal to zero
A roseira à uma cultura de grande valor no mercado interno e externo, devido a esse fato, as rosas geram benefÃcios para o estado do CearÃ. à uma cultura muito exigente em relaÃÃo à adubaÃÃo, sendo necessÃrios conhecimentos da fertilidade do solo, exigÃncias nutricionais da planta e eficiÃncia na utilizaÃÃo de nutrientes, para obtenÃÃo de uma adubaÃÃo adequada. Partindo a hipÃtese de que conhecendo-se o balanÃo nutricional da cultura, levando-se em consideraÃÃo a demanda de nutrientes pela cultura para alcanÃar uma dada produtividade e o suprimento de nutrientes pelo solo, à possÃvel determinar a quantidade de nutrientes a ser adicionada na fertilizaÃÃo do solo. O presente trabalho tem como objetivo determinar com base no balanÃo de nutrientes solo-planta a quantidade de nutrientes a ser adicionada no solo para cultura da roseira. O experimento foi conduzido na empresa Cearosa, em SÃo Benedito - CE, as plantas foram coletadas durante cinco meses, sendo uma vez por mÃs, amostrando cinco plantas aleatÃrias, de quatro cultivares de rosas: (Top Secret, Avalanche, Attache e Ambience). As partes aÃreas das plantas foram moÃdas e mineralizadas para determinaÃÃo dos teores dos nutrientes: N, P, K, Ca, Mg, S, B, Fe, Mn e Zn. Simultaneamente a coleta de plantas, tambÃm foram coletadas amostras de solo em duas profundidades, camada de 0 a 20 e de 20 a 40cm. Na qual foram submetidas à anÃlise de fertilidade. Para estimar a recomendaÃÃo de adubaÃÃo o sistema foi subdividido em: subsistema requerimento (REQ), que contempla a demanda de nutrientes pela planta, considerando a eficiÃncia de recuperaÃÃo dos nutrientes a serem aplicados, alÃm de uma dose que atende ao critÃrio de âsustentabilidadeâ e o subsistema suprimento (SUP), que corresponde à oferta de nutrientes pelo solo. ApÃs a determinaÃÃo do REQ total e SUP total, realizou -se o balanÃo nutricional, no qual se apresentar resultado positivo (REQ > SUP), recomenda-se a aplicaÃÃo de fertilizantes, e negativo ou nulo (REQ ≤ SUP), nÃo serà recomendado aplicar fertilizantes. O sistema estimou que o solo à capaz de suprir a demanda das plantas para P e Fe para todas as cultivares, no entanto, à necessÃrio que haja complementaÃÃo de adubaÃÃo nitrogenada, potÃssica. Assim como para os micronutrientes, o sistema estimou que hà necessidade de complementaÃÃo de adubaÃÃo, para Zn em todas as roseiras e Mn para as roseiras âTop secretâ e âAvalncheâ, no entanto com a recomendaÃÃo bem prÃximos a dose ideal, ou seja, igual a zero
Rose, Christopher. « Developing a nutrient recovery process for recovering nutrients in anaerobic digestate in low income countries ». Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9984.
Texte intégralCanals, Merseburger Mª Goretti. « Nutrient dynamics and metabolism in Mediterranean streams affected by nutrient inputs from human activities ». Doctoral thesis, Universitat de Barcelona, 2006. http://hdl.handle.net/10803/1434.
Texte intégralRhodes, Phillip Steven. « The interaction between maternal nutrient restriction and postnatal nutrient excess in an ovine model ». Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/12092/.
Texte intégralStock, Svenja [Verfasser]. « Plant nutrient mobilization and acquisition strategies : adaptation to water and nutrient availability / Svenja Stock ». Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1230138099/34.
Texte intégralKwan, Cheuk Hung. « Biosensors for biological nutrient monitoring / ». View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202004%20KWAN.
Texte intégralDe, Sousa Coelho Ana Luisa. « Metabolic signaling under nutrient deprivation ». Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/83459.
Texte intégralDurante su vida un individuo se somete a diversos cambios nutricionales. La capacidad de detectar la disponibilidad de nutrientes y regular la homeostasis energética es un proceso fundamental. SIRT1 es un regulador clave en el metabolismo energético. SIRT1 puede modular la expresión génica en tejidos metabólicamente activos en respuesta a la restricción calórica o el ayuno. La dependencia de la actividad deacetilasa de SIRT1 en los niveles de NAD+ constituye un vínculo fundamental entre el estado metabólico celular y la regulación de genes. FGF21 es una hormona que se induce en el ayuno y que afecta al metabolismo de los carbohidratos y de los lípidos. Recientemente se han demostrado sus efectos benéficos en la protección de la obesidad inducida por la dieta y en la mejoría en la resistencia a la insulina. En este trabajo hemos demostrado que en células hepáticas en cultivo, SIRT1 desempeña un papel importante en la activación por PPARα de la expresión de FGF21, CPT1A, HMGCS2, y PEPCK. También, que la actividad de SIRT1 regula los niveles de glicemia y la expresión de PCK1 en hígado, en la respuesta al ayuno. Aún así, hemos visto que la actividad de SIRT1 no afecta la expresión de los genes de la oxidación de los ácidos grasos o la cetogénesis en el hígado, en respuesta a diferentes cambios nutricionales, como la restricción calórica, la transición de la lactancia/destete, y el ayuno. Adicionalmente, hemos demostrado que la activación de FGF21 por SIRT1 depende de la actividad HMGCS2. También hemos descrito que FGF21 se induce por la privación de aminoácidos, de manera dependiente de ATF4, y hemos identificado dos elementos de respuesta funcionales en la región promotora del gene humano, altamente conservados entre las especies. Además, hemos demostrado que FGF21 interviene en la regulación del metabolismo de los lípidos en el hígado y el tejido adiposo blanco, y de la termogénesis en el tejido adiposo marrón, durante la privación de aminoácidos. De todas formas, hemos visto que la privación de leucina afecta a los niveles de ácidos grasos libres y cuerpos cetónicos en suero en el estado de alimentación, mientras que no lo hace en el ayuno; y la activación de FGF21 en el ayuno está afectada en los ratones alimentados con esta dieta, desvelando un “crosstalk” entre la señalización del ayuno y la privación de aminoácidos.
Felix, Leonardo Gama. « Nutrient Dynamics and Foods Webs ». Laboratório Nacional de Computação Científica, 2010. http://www.lncc.br/tdmc/tde_busca/arquivo.php?codArquivo=202.
Texte intégralUma rede trófica reúne as trocas de matéria e energia que ocorrem entre as espécies e entre o meio biótico e abiótico. Visto que os componentes abióticos formam a fonte de recursos basais, a abordagem deste trabalho consiste na avaliação dos efeitos da entrada de nutrientes alóctones em modelos estratégicos que descrevem a dinâmica de redes e cadeias tróficas, concentrando-se na determinação das características das populações de equilíbrio e das dinâmicas das espécies com diferentes respostas funcionais. Modelos estratégicos que contêm informações acerca do comportamento de populações interativas frente à entrada de nutrientes são uma base importante no delineamento de fenômenos gerais que podem ocorrer dentro da dinâmica de comunidades.
Falconer, Helen. « Personality differences and nutrient intake / ». Title page, contents and abstract only, 1990. http://web4.library.adelaide.edu.au/theses/09ARPS/09arpsf182.pdf.
Texte intégralNgai, Zoology. « Trophic effects on nutrient cycling ». Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2851.
Texte intégralRands, Marc Lawrence. « Nutrient flux in intracellular symbiosis ». Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306705.
Texte intégralSimmons, Tamla A. « Nutrient Transport by Shrimp Hepatopancreas ». UNF Digital Commons, 2012. http://digitalcommons.unf.edu/etd/420.
Texte intégralBrowning, Thomas John. « Nutrient limitation of marine phytoplankton ». Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:e250879e-131e-406a-a3cb-571e00dc0c81.
Texte intégralGedikoglu, Haluk McCann Laura. « Adoption of nutrient management practices ». Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/6614.
Texte intégralLoper, Shawna. « Diagnosing Nutrient Deficiencies Quick-Reference ». College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/312594.
Texte intégralNatho, Stephanie. « Modelling nutrient retention in floodplains ». Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2013. http://dx.doi.org/10.18452/16854.
Texte intégralAlthough there are detailed studies on nutrient retention in single wetlands and floodplains, the role of riparian floodplains for nutrient retention is not investigated very well on a landscape scale, since knowledge on the most important parameters for nutrient retention, inundated floodplains and incoming load, is insufficient. Additionally, a method for describing these parameters as discharge dependent variables is missing. Therefore, the present work analyzes the flooding frequencies on floodplains of three study rivers, Elbe, Main and Rhine. The relation of inundated floodplain extent and current discharge conditions based on detailed results of the established Software Flys is deduced empirically. Based on these subsequently generalized results, finally event related average inundated floodplain extent respectively, incoming nutrient loads are calculated by considering the effects of the hydrologic conditions of each river system. Therefore, available geodata as well as data on water quality and discharge is processed and serves as input data for yearly and monthly empirical retention models. The calculated nutrient retention in floodplains varies with hydrological connectivity of the floodplain to the surface waters as well as with the current hydrologic condition of the river system. For this reason the finally developed concept of event related nutrient retention is suggested as the most realistic in combination with hydro-exponential retention models. The Elbe floodplains are the most natural, and in years with high floods nutrient retention in the floodplains contributes up to 9% respectively 10% of the monthly transported load of TP and NO3-N, which is significant. The transfer of the results to a German-wide application is possible due the generalization of the methods carried out. With the presented results the hydrology dependent role of floodplains for nutrient balances in river systems can be quantified on a landscape scale.
Kiiskila, Steven Bert Roy. « Nutrient retranslocation of twelve Douglas-fir families in relation to productivity and site nutrient status ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0007/MQ32669.pdf.
Texte intégralHassan, Khalida Abdul-Karim. « The effect of soil conditions on nutrient availability, nutrient uptake and productivity of spring wheat ». Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329590.
Texte intégralRude, Christopher Mark. « Effects of feed manufacturing on nutrient metabolism, nutrient retention, and growth performance of broiler chickens ». Diss., Kansas State University, 2011. http://hdl.handle.net/2097/17152.
Texte intégralDepartment of Animal Sciences and Industry
R. Scott Beyer
Broiler chicken feed is processed. Cereal grains are ground to reduce particle size and the feed usually is pelleted. When pelleted, broiler diets are steam conditioned and forced through a die causing varying levels of starch gelatinization. Cereal grain particle size and starch gelatinization can be controlled during feed manufacturing. Earlier research has shown that starch gelatinization negatively affects growth performance of 0 to 21 d of age. An experiment was conducted to determine the effects of corn particle size and starch gelatinization on growth performance, dressing percentage, and gizzard size when fed to 22 to 42 d of age broilers. Increasing particle size from 470 to 1240 μm increased body weight gain, dressing percentage, and relative gizzard size. Starch gelatinization increased relative gizzard size. No interaction effects were detected. To expand on previous experiments, a trial was conducted to investigate the effect of starch gelatinization on broiler chick gastrointestinal pH, glucose absorption, and glucoregulation. Starch gelatinization level affected jejunum pH, with a higher pH reported at 20% starch gelatinization. Increases in starch gelatinization decreased blood glucose and increased glucagon level. Highest measured glucagon level was reported in broiler chicks fed the diet with 20% starch gelatinization level diet after 6 hours of starvation. A third experiment was conducted to determine the effect of starch gelatinization on metabolizable energy and amino acid digestibility. Increasing starch gelatinization from 0 to 100% increased true metabolizable energy and fecal output in roosters. No effect was found on apparent metabolizable energy or amino acid digestibility, with an increase in starch gelatinization from 0 to 20%. Increasing particle size from 470 to 1240 μm had a positive effect on 22 to 42 d growth performance. A starch gelatinization level of 20% or lower had no effect on metabolizable energy or amino acid digestion. Older broilers with larger gastrointestinal tracts are unaffected by 20% gelatinized starch; whereas, 20% gelatinized starch reduced blood glucose and increased glucagon levels of young broilers. Lower blood glucose and increased glucagon are indicative of lower glucose storage, and could cause reduced young broiler growth performance when fed diets with gelatinized starch.
Liu, Yingmei. « Effective Modeling of Nutrient Losses and Nutrient Management Practices in an Agricultural and Urbanizing Watershed ». Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/40398.
Texte intégralPh. D.
McManamay, Ryan A. « The effect of resource stoichiometry on fish and macroinvertebrate nutrient excretion ». Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/30780.
Texte intégralSimilar to theoretical predictions, fish and macroinvertebrate P excretion was negatively related to P content and the N:P excretion ratio was negatively related to the body N:P ratio. However, this relationship was driven primarily by two phosphorus rich species, mottled sculpin in the fish and crayfish in the macroinvertebrates. Some relationships did emerge between consumer excretion and diet. For example, hydropsychid caddisflies had the highest macroinvertebrate P excretion, possibly explained by the low N:P of seston. However, shredders, eating on a very low N and P diet of leaf detritus, had very low N and P excretion.
The relationship between consumers, their food, and nutrient excretion is a matter of mass balance. If the food N:P ratio is higher than that of the consumer, then the N:P excretion should be higher than the consumer N:P and the food N:P, especially if organisms are P-limited. However, N:P excretion by macroinvertebrates and fish were very similar despite large differences in diet. The majority of macroinvertebrates and fish had a lower N:P excretion ratio than the predicted N:P of their food, possibly indicating that 1) consumers were either selectively consuming more P-rich foods than the diets that I assigned them or 2) consumers are generally not N or P limited or influenced by the N or P in their diet. Mottled sculpin and crayfish were the only organisms with a higher N:P excretion than their resources and both had a higher %P than the other fish and macroinvertebrates, respectively. High N:P excretion along with high phosphorus content is indicative of P-limitation. Macroinvertebrates and fish, excluding mottled sculpin and crayfish, had a lower N:P excretion and the N:P ratio of the water column. If consumers do play a role in nutrient dynamics, then consumers could alter the relative abundance of nitrogen and phosphorus by supplying more phosphorus. However, the presence of a P-limited organism, such as mottled sclupin or crayfish, could alter the relative abundance of nitrogen and phosphorus by supplying less phosphorus.
Master of Science
Deus, Josà Aridiano Lima de. « Sistema de recomendaÃÃo de corretivos e fertilizantes para o meloeiro com base no balanÃo nutricional ». Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8145.
Texte intégralO meloeiro à uma das cucurbitÃceas mais exigentes em relaÃÃo à adubaÃÃo, sendo necessÃrios conhecimentos de solo, exigÃncia nutricional e eficiÃncia na utilizaÃÃo de nutrientes, para uma adubaÃÃo adequada. Objetivou-se a parametrizaÃÃo de um sistema para recomendaÃÃo de corretivos e fertilizantes para a cultura do meloeiro (Ferticalc-MelÃo) com base no balanÃo nutricional. O sistema apresenta um mÃdulo para correÃÃo da acidez no solo utilizando dois mÃtodos de recomendaÃÃo de calagem. Para estimar a adubaÃÃo recomendada o sistema foi subdividido: subsistema requerimento (REQ), que contempla a demanda de nutrientes pela planta, considerando a eficiÃncia de recuperaÃÃo dos nutrientes aplicados, alÃm de uma dose que atende ao critÃrio de âsustentabilidadeâ apenas para o nutriente K, e o subsistema suprimento (SUP), que corresponde à oferta de nutrientes pelo solo e Ãgua de irrigaÃÃo. ApÃs a determinaÃÃo do REQtotal e SUPtotal, realizou-se o balanÃo nutricional, no qual em resultado positivo (REQ > SUP), recomenda-se a aplicaÃÃo de fertilizantes, e negativo ou nulo (REQ ≤ SUP), nÃo se recomenda aplicar. Foram feitas simulaÃÃes para quatro diferentes tipos de meloeiro: Amarelo, Cantaloupe, GÃlia e Pele-de-sapo, numa faixa de produtividade esperada total de 15.000 a 45.000 kg ha-1 considerando diferentes valores de P-rem. O sistema estimou que o GÃlia foi o menos exigente em P enquanto o Pele-de-sapo mostrou-se mais exigente. Dentre os tipos, o Cantaloupe foi menos exigente em N e Ca, enquanto o Amarelo exigiu menos K, Mg e S. Para os micronutrientes, o Amarelo foi o que menos exigiu Fe, Cu e Zn, enquanto Mn foi menos demandado pelo Cantaloupe. O suprimento dos nutrientes K, Ca e Mg pela Ãgua de irrigaÃÃo foram respectivamente, 23,40; 1.216,00 e 136,08 kg ha-1 para as condiÃÃes de solo (AS - I) e 6,24; 48,00 e 4,86 kg ha-1 para (AS-II). De maneira geral, o sistema recomendou adubaÃÃo com macronutrientes para (AS-II) com exceÃÃo para Mg e Ca, enquanto para (AS-I) foi recomendado apenas para N e P, em funÃÃo dos altos teores de K, Ca e Mg no solo e Ãgua de irrigaÃÃo. Comparando com outros mÃtodos o sistema mostrou-se mais dinÃmico e flexÃvel nas suas recomendaÃÃes. AtravÃs da anÃlise de sensibilidade do sistema, constatou que a variÃvel que mais influenciou as recomendaÃÃes foi a produtividade, seguida dos teores de nutriente no solo. O sistema apresentou resultados satisfatÃrios em relaÃÃo Ãs recomendaÃÃes, porÃm necessita ser avaliado sob condiÃÃes de campo para seu aperfeiÃoamento em futuras versÃes.
The melon is one of cucurbitaceae most demanding in relation to fertilization, being necessary knowledge of soil, nutritional requirements and nutrient use efficiency, for a proper fertilization. The objective was parameterization of a system for recommendation of fertilizers for the melon (Ferticalc-Melon) based on the nutrient balance. The system features a module for soil acidity correction using two methods of liming. To estimate the fertilizer recommended, the system was subdivided: requirement subsystem (REQ), which includes the demand for nutrients by the plant, whereas the efficiency of nutrient recovery, and a dose that meets the criterion of "sustainability" only for the nutrient K, and supply subsystem (SUP), which corresponds to the supply of nutrients from the soil and irrigation water. After determining the REQamount and SUPamount, held the nutritional balance, in which a positive result (REQ > SUP), it is recommended that the application of fertilizer, and negative or zero (REQ ≤ SUP), not recommended to apply. Simulations were made for four different types of melon: Amarelo, Cantaloupe, GÃlia e Pele-de-sapo, in the range of productivity expected total of 15,000 to 45,000 kg ha-1 considering different values of P-rem. The system estimated that the GÃlia was the least demanding in P while Pele-de-sapo was the most demanding. Among the types, Cantaloupe was the least demanding in N and Ca, while the Amarelo requires less K, Mg and S. For the micronutrients, Amarelo was the least demanded that Fe, Cu and Zn, whereas Mn was less demanded by Cantaloupe. The supply of nutrients K, Ca and Mg by irrigation water were respectively, 23.40; 1,216.00 e 136.08 kg ha-1 to soil conditions (AS - I) and 6.24; 48.00 and 4.86 kg ha-1 to (AS-II). In general, the system recommended fertilization with macronutrients for (AS-II) except for Mg and Ca, while for (AS-I) was recommended only N and P, due to high levels of K, Ca and Mg in the soil and irrigation water. Compared with other methods the system proved to be more dynamic and flexible in its recommendations. By analyzing the sensitivity of the system, found that the variable that most influenced the recommendations was the productivity, then the nutrient content in soil. The system showed good results in relation to the recommendations, but needs to be evaluated under field conditions for your improvement in future versions.
Zhang, Bo Zhi. « Reducing Nutrient Excretion via Improved Nutrient Utilization by Supplementing Pig and Poultry Diets with Phytase Enzyme ». Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/26245.
Texte intégralPh. D.
Sainsbury, Jeanine. « Nutrient content and carcass composition of South African mutton with a focus on bioavailability of selected nutrients ». Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-11302009-190302/.
Texte intégralAl-Lagtah, Nasir Mohammed A'mro. « Nutrient biodegradation in sequential batch reactor ». Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491979.
Texte intégralO'Brien, Patrick Charles. « Nutrient sensing in the alimentary tract ». Thesis, King's College London (University of London), 2016. https://kclpure.kcl.ac.uk/portal/en/theses/nutrient-sensing-in-the-alimentary-tract(0b0e7cce-f887-4a4e-8ba4-8c6dde4d65c8).html.
Texte intégralHansler, Susan. « Compositional simulation of nutrient-limited bioventing ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0027/MQ50342.pdf.
Texte intégralStålnacke, Per. « Nutrient loads to the Baltic Sea / ». Linköping : Univ, 1996. http://www.bibl.liu.se/liupubl/disp/disp96/arts146s.htm.
Texte intégralAndréasson, Claes. « Ligand-activated proteolysis in nutrient signaling / ». Stockholm, 2004. http://diss.kib.ki.se/2004/91-7140-075-3/.
Texte intégralGatenby, Lisa Ann. « Nutrient intakes of primary school children ». Thesis, University of Hull, 2008. http://hydra.hull.ac.uk/resources/hull:761.
Texte intégralEarl, Timothy J. « Modelling nutrient loads from British catchments ». Thesis, University of Essex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495764.
Texte intégralRizvi, Abbas. « Systems Level Studies of Nutrient Homeostasis ». Thesis, Harvard University, 2011. http://dissertations.umi.com/gsas.harvard:10022.
Texte intégralOtt, Alexandra. « Nutrient acquisition by downy mildew fungi ». Thesis, University of the West of England, Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418447.
Texte intégralRoose, T. « Mathematical model of plant nutrient uptake ». Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365790.
Texte intégralMills, Carolyn Lesley. « The nutrient economy of grazed grassland ». Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361226.
Texte intégralKamperidis, Nikolaos. « Nutrient effects in inflammatory bowel disease ». Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/23488.
Texte intégralMagar, Vanesa. « Nutrient uptake by a squirming microorganism ». Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621400.
Texte intégralKrige, Graeme Tertius. « Nutrient management strategies for nectarine orchards ». Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/21667.
Texte intégralENGLISH ABSTRACT: The macro-element uptake and distribution by higher density central leader ‘Donnarine’ nectarine trees was studied through the sequential excavation of trees. A large portion, 41.5%, of the nitrogen manifested in the new growth from dormancy up to pit-hardening, originated from nitrogen reserves in the permanent structure. The permanent structure was also an important source of phosphorous reserves. Of the phosphorous in the fruit, leaves and new shoots at pit-hardening, 35.0% came from reserves in the permanent structure. Potassium did not act as an important reserve in the nectarine trees and was taken up throughout the season. From pit hardening to harvest the fruit represented the most important sink for potassium. Calcium and magnesium, like potassium, did not play significant roles as reserves in the nectarine tree and must be available for uptake from the beginning of the season for new growth and development as well as fruit quality. The micro-element uptake and distribution was also studied through the sequential excavation of the same ‘Donnarine’ nectarine trees. Little scientific data is available on this topic. Manganese and iron was found to act as important reserves in the tree with 46.2% of manganese and 59.5% of the iron found in the new growth at pithardening coming from reserves translocated from the permanent structure. Zinc and boron reserves also play a role in nectarine trees, but to a lesser extent than manganese and iron. The seasonal mineral nutrient demand of the same ‘Donnarine’ nectarine trees was determined through the sequential excavation of trees and losses and fixation was calculated. Guidelines regarding nutritional requirements per ton of fruit produced per hectare by higher density nectarine orchards are respectively 3.82kg nitrogen, 0.35kg phosphorous, 4.43kg potassium, 1.53kg calcium, 0.52kg magnesium, 32.45g sodium, 9.44g manganese, 37.46g iron, 3.24g copper, 13.95g zinc and 10.52g boron. Sodium is not commonly considered to be essential to higher plants, but was included in the trial. Nutrient solutions with four different EC (electrical conductivity) levels were applied to ‘Donnarine’ nectarine trees under pulsating drip fertigation for three periods of different lengths, before harvest. Raising the nutrient solution EC to positively affect fruit quality is a technique widely utilised in the vegetable industry. This technique did, however, not have similar positive effects on nectarine fruit grown under a pulsating drip fertigation system. Good production practices such as accurate nutrition and irrigation as well as the correct horticultural inputs should be the primary focus of producers who wish to alter or improve the fruit quality of their crop.
AFRIKAANSE OPSOMMING: Voedingbestuur strategieë in nektarien boorde Die makro-element opname en verspreiding deur hoër digtheid sentrale leier ‘Donnarine’ nektarien bome is bestudeer d.m.v. opeenvolgende opgrawings van volledige bome en die ontleding van monsters. ‘n Groot hoeveelheid, 41.5%, van die stikstof wat tydens pitverharding in die nuwe groei teenwoordig was, is d.m.v. translokasie vanuit die permanente struktuur van die boom afkomstig. Die permanente struktuur was ook ‘n belangrike bron van fosfaat reserwes. Teen pitverharding was 35.0% van die fosfaat in die nuwe groei afkomstig vanuit die permanente struktuur. Bevindings het getoon dat kalium nie as ‘n reserwe in die nektarien bome opgetree het nie en dié element is deur die groeiseisoen opgeneem. Vanaf pitverharding tot en met oestyd was die vrugte die sterkste setel van aanvraag vir kalium. Kalsium en magnesium het, soos in die geval van kalium, nie ‘n belangrike rol as reserwe vertolk nie. Beskikbaarheid van hierdie elemente vir opname vanaf die begin van die groeiseisoen is dus baie belangrik vir nuwe groei en ontwikkeling asook vrugkwaliteit. Die mikro-element opname en distribusie van dieselfde ‘Donnarine’ nektarien bome is ook bestudeer d.m.v. opeenvolgende opgrawings en analise van volledige bome. Min wetenskaplike literatuur oor hierdie onderwerp is beskikbaar. Bevindings het getoon dat mangaan asook yster baie belangrike reserwes in die nektarien boom is. Tydens pitverharding was 46.2% van die mangaan en 59.5% van die yster wat in die nuwe groei teenwoordig was, afkomstig vanaf reserwes uit die permanente struktuur van die boom. Verder het sink en boor ook as reserwes opgetree, maar tot ‘n mindere mate as mangaan en yster. Die seisoenale behoeftes aan minerale voeding van dieselfde ‘Donnarine’ nektarien bome is bepaal d.m.v. opeenvolgende opgrawings en analise van volledige bome asook die bepaling van verwyderingsverliese en vaslegging. Voedingsriglyne is vasgestel i.t.v. die hoeveelheid voedingstof wat per hektaar benodig word om een ton nektariens te produseer. Die riglyne is as volg: 3.82kg stikstof, 0.35kg fosfaat, 4.43kg kalium, 1.53kg kalsium, 0.52kg magnesium, 32.45g natrium, 9.44g mangaan, 37.46g yster, 3.24g koper, 13.95g sink en 10.52g boor. Natrium word nie in die algemeen as ‘n essensiële plantvoedingselement beskou nie, maar is by die berekeninge ingesluit. Voedingsoplossing met vier verskillende vlakke van EG (elektriese geleiding) is vir drie periodes van verskillende lengtes aan ‘Donnarine’ nekarien bome toegedien. Die verhoging van die EG van voedingsoplossings ten einde kwaliteit te verbeter is ‘n tegniek wat met groot suskses in die groentbedryf toegepas word. Hierdie tegniek het egter nie soortgelyke positiewe effekte op die nektarien vrugkwaliteit gehad nie. Produsente wat hul vrugkwaliteit wil verbeter behoort primêr te fokus op goeie produksiepraktyke soos akkurate voeding en besproeiing asook die korrekte tuinboukundige insette.