992 resultados para 338.962
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2003
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A avaliacao de cultivares de trigo no Parana, com fins de recomendacao, e realizada pelas Instituicoes: IAPAR, Embrapa Soja, COODETEC e Fundacao Agraria de Pesquisa, atraves da instalacao de ensaios de rendimento nas principais regioes triticolas do Estado. Sao relatados os resultados obtidos em 1996 de 17 experimentos do Ensaio Intermediario Paranaense (IPR), 25 experimentos do Centro-Sul Brasileiro (CSBR) e 24 experimentos do Ensaio em Cultivo (ECR), para solos com aluminio, instalados em Londrina, Faxinal, Campo Mourao, Cascavel, Pato Branco, Arapoti, Tibagi, Ponta Grossa e Guarapuava, representando as regioes Norte, Oeste, Sudoeste e Sul do Estado. Os rendimentos dos ensaios instalados em Faxinal foram prejudicados por chuva de granizo. Devido a pouca precipitação, os ensaio instalados em Londrina e Cascavel receberam irrigacao, para assegurar a emergencia uniforme das plantas. A ocorrencia de doencas foi muito baixa, principalmente nas regioes Norte e Oeste. No Sul e Sudoeste, onde a precipitacao foi mais elevada, ocorreu maior incidencia de doencas fungicas e os pesos do hectolitro foram menores. Em alguns experimentos obteve-se produtividade media superior a 5 t/ha, considerada elevada para o trigo. No ensaio IPR, foram promovidas, em funcao do rendimento e outras caracteristicas, as linhagens OC 962, OC 963, OC 968, ORL 93320, PF 90120 e PF 9293. No CSBR, destacaram-se e foram mantidas as linhagens OC 959, OC 9511, ORL 9285, PF 9099, PF 91205 e PG 9337. No ECR, destacaram-se, em mais de uma regiao, as cultivares EMBRAPA-27, OR 1, IAPAR 46, IAPAR 60, IAPAR 78 e T. BR 23.
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O estado do Parana apresenta uma diversidade de clima, com invernos irregulares em relacao a precipitacoes pluviometricas e ocorrencia de geadas, e tambem, com relacao aos tipos de solos, que influem na adaptacao e no desempenho dos genotipos de trigo. Em vista disto, ha necessidade de um maior numero de cultivares, com caracteristicas diferenciadas para serem utilizadas pelos produtores. O presente trabalho tem por objetivo avaliar, nas zonas A e B, em solos com ate 5% de saturacao de aluminio, os novos genotipos de trigo criados pelas diferentes instituicoes que desenvolvem trabalhos de melhoramento genetico de trigo. Esta avaliacao e realizada pelo Instituto Agronomico do Parana (IAPAR), pelo Centro Nacional de Pesquisa de Soja (Embrapa Soja) e pela Cooperativa Central de Desenvolvimento Tecnologico e Economico (COODETEC), atraves da instalacao de diferentes ensaios de competicao de genotipos. Os resultados aqui relatados sao resultantes de dez experimentos do Ensaio Intermediario Paranaense (IPS), doze experimentos do Ensaio Centro-Sul Brasileiro (CSBS) e onze experimentos do Ensaio de Cultivares em Cultivo (ECS), para solos com ate 5% de saturacao de aluminio, instalados em 1996, em diferentes epocas, nas localidade de Cambara, Londrina, Engenheiro Beltrao, Palotina e Sao Miguel do Iguacu. Devido a longa estiagem ocorrida no periodo de abril a julho, no Norte do estado (zona A1), alguns experimentos foram prejudicados e, outros perdidos. Em Londrina e Palotina, os experimentos receberam irrigacoes na fase inicial para propiciar uma boa germinacao e desenvolvimento das plantas. A incidencia de molestias foi baixa, em ambas as zonas predominando no entanto, uma razoavel infeccao de oidio, nas semeaduras mais tardias, e de ferrugem da folha. Observou-se uma variabilidade dos genotipos quanto ao grau de tolerancia e/ou suscetibilidade a estas molestias, como tambem, uma resposta no rendimento de graos ao controle destas, pelo uso de fungicidas especificos. Os rendimentos obtidos, em geral, foram muitos bons, alcancando, em alguns casos, a 6,7 t/ha. No ensaio IPS, em funcao do rendimento de graos e outras caracteristicas, foram selecionadas as linhagens IA 952, IWT 9430, LD 941, LD 946, OC 962, OC 963, OC 965, ORL 92203 e PR 961. NO CSBS, foram mantidas as linhagens IOR 90226 e PF 91450. No ECS, destacaram-se, em ambas as zonas, as cultivares IAPAR 60, IAPAR 78 e OR 1. Considerando os resultados de rendimentos de graos e outras caracteristicas agronomicas e, principalmente, a qualidade da farinha para panificacao, foram recomendadas como novas cultivares, as linhagens IDS 934-21 e OC 939, denominadas, respectivamente, de Manitoba 97 e COODETEC 101.
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The aim of the present study was to assess the factors which may influence the timing of the introduction of solid food to infants. The design was a prospective cohort study by interview and postal questionnaire. Primiparous women (n 541) aged between 16 and 40 years were approached in the Forth Park Maternity Hospital, Fife, Scotland. Of these, 526 women agreed to participate and seventy-eight were used as subjects in the pilot study. At 12 weeks we interviewed 338 women of the study sample. The postal questionnaire was returned by 286 of 448 volunteers. At 12 weeks 133 of 338 mothers said that they had introduced solids. Those that said that they had introduced solids early (<12 weeks) were compared with those who had introduced solids late (>12 weeks) by bivariate and multiple regression analysis. Psychosocial factors influencing the decision were measured with the main outcome measure being the time of introduction of solid food. The early introduction of solids was found to be associated with: the opinions of the infant's maternal grandmother; living in a deprived area; personal disagreement with the advice to wait until the baby was 4 months; lack of encouragement from friends to wait until the baby was 4 months; being in receipt of free samples of manufactured food. Answers to open-ended questions indicated that the early introduction appeared to be influenced by the mothers’ perceptions of the baby's needs. Some of the factors influencing a woman's decision to introduce solids are amenable to change, and these could be targeted in educational interventions.
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Burnley, M, Doust, J and Jones, A (2005) Effects of Prior Warm-up Regime on Severe-Intensity Cycling Performance. Medicine and Science in Sports and Exercise, 37 (5). pp. 838-845. ISSN 1530-0315 RAE2008
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Burnley, M., Doust, J. and Jones, A. (2006). Time required for the restoration of normal heavy exercise Vo(2) kinetics following prior heavy exercise. Journal of Applied Physiology. 101(5), pp.1320-1327 RAE2008
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Williams, Mike, 'Why ideas matter in International Relations: Hans Morgenthau, Classical Realism, and the Moral Construction of Power Politics', International Organization (2004) 58(4) pp.633-665 RAE2008
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En Tomo V. 2 h. de grabados calcográficos representando monedas de Huesca.
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18 fotografías a color.
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Acute myeloid leukaemia refers to cancer of the blood and bone marrow characterised by the rapid expansion of immature blasts of the myeloid lineage. The aberrant proliferation of these blasts interferes with normal haematopoiesis, resulting in symptoms such as anaemia, poor coagulation and infections. The molecular mechanisms underpinning acute myeloid leukaemia are multi-faceted and complex, with a range of diverse genetic and cytogenetic abnormalities giving rise to the acute myeloid leukaemia phenotype. Amongst the most common causative factors are mutations of the FLT3 gene, which codes for a growth factor receptor tyrosine kinase required by developing haematopoietic cells. Disruptions to this gene can result in constitutively active FLT3, driving the de-regulated proliferation of undifferentiated precursor blasts. FLT3-targeted drugs provide the opportunity to inhibit this oncogenic receptor, but over time can give rise to resistance within the blast population. The identification of targetable components of the FLT3 signalling pathway may allow for combination therapies to be used to impede the emergence of resistance. However, the intracellular signal transduction pathway of FLT3 is relatively obscure. The objective of this study is to further elucidate this pathway, with particular focus on the redox signalling element which is thought to be involved. Signalling via reactive oxygen species is becoming increasingly recognised as a crucial aspect of physiological and pathological processes within the cell. The first part of this study examined the effects of NADPH oxidase-derived reactive oxygen species on the tyrosine phosphorylation levels of acute myeloid leukaemia cell lines. Using two-dimensional phosphotyrosine immunoblotting, a range of proteins were identified as undergoing tyrosine phosphorylation in response to NADPH oxidase activity. Ezrin, a cytoskeletal regulatory protein and substrate of Src kinase, was selected for further study. The next part of this study established that NADPH oxidase is subject to regulation by FLT3. Both wild type and oncogenic FLT3 signalling were shown to affect the expression of a key NADPH oxidase subunit, p22phox, and FLT3 was also demonstrated to drive intracellular reactive oxygen species production. The NADPH oxidase target protein, Ezrin, undergoes phosphorylation on two tyrosine residues downstream of FLT3 signalling, an effect which was shown to be p22phox-dependent and which was attributed to the redox regulation of Src. The cytoskeletal associations of Ezrin and its established role in metastasis prompted the investigation of the effects of FLT3 and NADPH oxidase activity on the migration of acute myeloid leukaemia cell lines. It was found that inhibition of either FLT3 or NADPH oxidase negatively impacted on the motility of acute myeloid leukaemia cells. The final part of this study focused on the relationship between FLT3 signalling and phosphatase activity. It was determined, using phosphatase expression profiling and real-time PCR, that several phosphatases are subject to regulation at the levels of transcription and post-translational modification downstream of oncogenic FLT3 activity. In summary, this study demonstrates that FLT3 signal transduction utilises a NADPH oxidase-dependent redox element, which affects Src kinase, and modulates leukaemic cell migration through Ezrin. Furthermore, the expression and activity of several phosphatases is tightly linked to FLT3 signalling. This work reveals novel components of the FLT3 signalling cascade and indicates a range of potential therapeutic targets.
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Solar Energy is a clean and abundant energy source that can help reduce reliance on fossil fuels around which questions still persist about their contribution to climate and long-term availability. Monolithic triple-junction solar cells are currently the state of the art photovoltaic devices with champion cell efficiencies exceeding 40%, but their ultimate efficiency is restricted by the current-matching constraint of series-connected cells. The objective of this thesis was to investigate the use of solar cells with lattice constants equal to InP in order to reduce the constraint of current matching in multi-junction solar cells. This was addressed by two approaches: Firstly, the formation of mechanically stacked solar cells (MSSC) was investigated through the addition of separate connections to individual cells that make up a multi-junction device. An electrical and optical modelling approach identified separately connected InGaAs bottom cells stacked under dual-junction GaAs based top cells as a route to high efficiency. An InGaAs solar cell was fabricated on an InP substrate with a measured 1-Sun conversion efficiency of 9.3%. A comparative study of adhesives found benzocyclobutene to be the most suitable for bonding component cells in a mechanically stacked configuration owing to its higher thermal conductivity and refractive index when compared to other candidate adhesives. A flip-chip process was developed to bond single-junction GaAs and InGaAs cells with a measured 4-terminal MSSC efficiency of 25.2% under 1-Sun conditions. Additionally, a novel InAlAs solar cell was identified, which can be used to provide an alternative to the well established GaAs solar cell. As wide bandgap InAlAs solar cells have not been extensively investigated for use in photovoltaics, single-junction cells were fabricated and their properties relevant to PV operation analysed. Minority carrier diffusion lengths in the micrometre range were extracted, confirming InAlAs as a suitable material for use in III-V solar cells, and a 1-Sun conversion efficiency of 6.6% measured for cells with 800 nm thick absorber layers. Given the cost and small diameter of commercially available InP wafers, InGaAs and InAlAs solar cells were fabricated on alternative substrates, namely GaAs. As a first demonstration the lattice constant of a GaAs substrate was graded to InP using an InxGa1-xAs metamorphic buffer layer onto which cells were grown. This was the first demonstration of an InAlAs solar cell on an alternative substrate and an initial step towards fabricating these cells on Si. The results presented offer a route to developing multi-junction solar cell devices based on the InP lattice parameter, thus extending the range of available bandgaps for high efficiency cells.
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BACKGROUND: Like other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. Although associative, social learning is typically credited for discrimination of familiar kin, discrimination of unfamiliar kin remains unexplained. As sex-biased dispersal in long-lived species cannot consistently prevent encounters between unfamiliar kin, inbreeding remains a threat and mechanisms to avoid it beg explanation. Using a molecular approach that combined analyses of biochemical and microsatellite markers in 17 female and 19 male ring-tailed lemurs (Lemur catta), we describe odor-gene covariance to establish the feasibility of olfactory-mediated kin recognition. RESULTS: Despite derivation from different genital glands, labial and scrotal secretions shared about 170 of their respective 338 and 203 semiochemicals. In addition, these semiochemicals encoded information about genetic relatedness within and between the sexes. Although the sexes showed opposite seasonal patterns in signal complexity, the odor profiles of related individuals (whether same-sex or mixed-sex dyads) converged most strongly in the competitive breeding season. Thus, a strong, mutual olfactory signal of genetic relatedness appeared specifically when such information would be crucial for preventing inbreeding. That weaker signals of genetic relatedness might exist year round could provide a mechanism to explain nepotism between unfamiliar kin. CONCLUSION: We suggest that signal convergence between the sexes may reflect strong selective pressures on kin recognition, whereas signal convergence within the sexes may arise as its by-product or function independently to prevent competition between unfamiliar relatives. The link between an individual's genome and its olfactory signals could be mediated by biosynthetic pathways producing polymorphic semiochemicals or by carrier proteins modifying the individual bouquet of olfactory cues. In conclusion, we unveil a possible olfactory mechanism of kin recognition that has specific relevance to understanding inbreeding avoidance and nepotistic behavior observed in free-ranging primates, and broader relevance to understanding the mechanisms of vertebrate olfactory communication.