Orientador: Sebastião Araujo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T08:30:37Z (GMT). No. of bitstreams: 1 Figueiredo_LucianaCastilhode_D.pdf: 2533700 bytes, checksum: 33bede305be3c550ada42648ae70b2f1 (MD5) Previous issue date: 2008 / ResumoObjetivo: Comparar os índices de trocas gasosas no pós-operatório de pacientes submetidos à revascularização do miocárdio (RM) que receberam ou não pressão positiva contínua nas vias aéreas (CPAP) durante a circulação extracorpórea (CEC). Método: Trinta pacientes adultos submetidos à RM com CEC no período de março a setembro de 2005 foram alocados aleatoriamente em dois grupos: CPAP (n=15), pacientes que utilizaram CPAP a 10 cmH2O durante a CEC, e controle (n=15), pacientes que não utilizaram CPAP. Foram analisados a PaO2/FiO2 e o P(A-a)O2 em quatro momentos: Pré (logo antes da CEC, com FiO2 = 1,0); Pós (30min pós-CEC, com FiO2 = 1,0); PO imediato (12h após a cirurgia, com FiO2 = 0,4 utilizando máscara facial) e 1º PO (24 horas após a cirurgia, com FiO2 = 0,5 utilizando máscara facial). Resultados: A PaO2/FiO2 e o P(A-a)O2 mostraram uma piora significativa no decorrer do tempo dentro de cada grupo, porém sem diferenças significativas entre os grupos em nenhum momento. Quando a PaO2/FiO2 foi subdividida em três categorias, foi observada uma maior prevalência de pacientes do grupo CPAP com valores acima de 200mmHg (p=0,02) apenas no momento Pós (30min pós-CEC). Conclusão: O uso de CPAP de 10cmH2O durante a CEC, muito embora tenha resultado em melhores valores na PaO2/FiO2 30 minutos pós-CEC, não resultou em benefícios duradouros nas trocas gasosas durante o PO. Concluiu-se que, em pacientes submetidos à RM, a aplicação de CPAP 10cmH2O não melhora significativamente as trocas gasosas pulmonares no pós-operatório. / Abstract: Objective: To compare postoperative (PO) pulmonary gas exchange indexes in patients submitted to myocardial revascularization (MR) with or without the application of continuous positive airway pressure (CPAP) during cardiopulmonary bypass (CPB). Methods: Thirty adult patients submitted to MR with CPB between March and September 2005 were randomly allocated to two groups: CPAP (n=15), patients that received CPAP at 10 cmH2O during CPB, and control (n=15), patients that didn't receive CPAP. PaO2/FiO2 and P(A-a)O2 were analyzed at four moments: Pre (just before CPB, with FiO2 = 1.0 ); Post (30min post-CPB, with FiO2 = 1.0); immediate PO period (12h post-surgery, with FiO2 = 0.4 by a facial mask) and first PO day (24h post-surgery, with FiO2 = 0.5 by a facial mask). Results: PaO2/FiO2 and P(A-a)O2 tend to get significantly worst as time elapsed during the postoperative period in both groups, but no differences were observed between them at any moment. When PaO2/FiO2 was subdivided into three categories, a greater prevalence of patients with values greater than 200 mmHg were observed in CPAP group only at moment Post (30min post-CPB; p = 0.02). Conclusion: CPAP at 10 cmH2O administered during CPB, although had lightly improved PaO2/FiO2 at 30 minutes post-CPB, had no significant sustained effect on postoperative pulmonary gas exchange. It was concluded that in patients submitted to MR, application of 10 cmH2O CPAP does not improve postoperative pulmonary gas exchange. / Doutorado / Pesquisa Experimental / Doutor em Cirurgia

Made available in DSpace on 2014-08-20T13:59:07Z (GMT). No. of bitstreams: 1 dissertacao_aline_alves_messchmidt.pdf: 535406 bytes, checksum: d041feac45e14506cfa6fba63d16e35c (MD5) Previous issue date: 2013-12-20 / The Rio Grande do Sul has the largest peach producing area of the country, but its productivity is still low when compared with other Brazil´s states. One of the problems related to low productivity are soils with poor drainage and low water storage capacity, mainly in the producing region of Pelotas, as well as the presence of root-knot nematodes (Meloidogyne spp.) on the orchards, whose damages have great importance because the novice action on the root system, affecting the nutrient and water absorption and translocation. These stresses can cause physiological changes in plants affecting fruit quality and productivity of orchards. The objective of this study was to evaluate the effects of these stresses on peach plants of rootstock cv. Capdeboscq, Flordaguard and plum rootstock cv. Mirabolano 29-C. The study was divided into two experiments. At first, we evaluated gas exchange and antioxidant enzymes activity of Prunus rootstocks submitted to the following stresses treatments: a) Waterlogging, for eight days; b) drought for eight days; and c) control, with regular plant watering. After the stresses period, plants returned to normal water regime. The Mirabolano 29-C rootstock shown to be more susceptible to drought than waterlogging, compared to the two peach rootstocks evaluated. On the other hand, Flordaguard and Capdeboscq shown more damages when the plants were subjected to waterlogging, verified by the higher rate of lipid peroxidation in relation to the control plants of these cultivars. The second experiment evaluated the effects of M. javanica plant-inoculation on the reproduction factor (RF) and gas exchange. 150 days after inoculation, the plants of cvs. Capdeboscq, Flordaguard, and Mirabolano C-29 were susceptible (FR = 1.77), resistant, and immune, respectively. In relation to gas exchange, only the inoculated plants of cv. Capdeboscq showed higher stomatal conductance, internal CO2 concentration and transpiration, and reduced efficiency in water use. For other genotypes there were no significant effects on the variables analyzed. / O Rio Grande do Sul possui a maior área de produção de pêssego do Brasil, porém sua produtividade ainda é baixa quando comparado com outros estados. Um dos problemas relacionados à baixa produtividade são os solos com problemas de drenagem e baixa capacidade de armazenar água, principalmente na região produtora de Pelotas, assim como a presença de nematóides causadores de galhas nas raízes (Meloidogyne spp.), cujos danos têm grande importância em virtude da ação nociva sobre o sistema radicular, afetando a absorção e a translocação de água e nutrientes. Esses estresses podem causar alterações fisiológicas nas plantas, comprometendo a qualidade dos frutos e a produtividade dos pomares. O objetivo do presente trabalho foi avaliar os efeitos destes fatores de estresse nos portaenxertos de pessegueiro cv. Capdeboscq, Flordaguard e ameixeira cv. Mirabolano 29-C. O trabalho foi dividido em dois experimentos. No primeiro, avaliou-se as trocas gasosas e atividade antioxidante de portaenxertos do gênero Prunus submetidos aos seguintes tratamentos de estresse: a) alagamento do solo, por oito dias b) seca, por oito dias e c) controle, com irrigação conforme necessidade das plantas. Após o período de estresse, as plantas retornaram às condições normais de regime hídrico. O portaenxerto Mirabolano 29-C demonstrou ser mais suscetível ao déficit hídrico do que ao alagamento, quando comparado as duas cultivares de pessegueiro avaliadas. Por outro lado, nas cvs. Flordaguard e Capdeboscq ocorreram maiores danos quando as plantas foram submetidas ao alagamento, verificado por meio da maior taxa de peroxidação lipídica, em relação as plantas controle destas cultivares. No segundo experimento, avaliaram-se os efeitos da inoculação de Meloidogyne javanica sobre o fator de reprodução (FR) e das trocas gasosas. Aos 150 dias após a inoculação, as plantas das cvs. Capdeboscq, Flordaguard e Mirabolano 29-C mostraram-se suscetíveis (FR=1,77), resistentes e imunes, respectivamente. Em relação às trocas gasosas, apenas as plantas inoculadas da cv. Capdeboscq apresentaram maiores valores de condutância estomática, concentração intracelular de CO2 e de transpiração, e uma menor eficiência no uso da água. Para os demais genótipos não houve efeitos significativos nas variáveis analisadas.

Dans le contexte du changement climatique, les prédictions réalisées mettent en évidence une altération de la disponibilité en eau dans de nombreuses régions viticoles ; ce qui, conjointement à l’augmentation de la population mondiale et la diminution des terres agricoles, va accroître la compétition pour l’utilisation des ressources hydriques. Par conséquent, améliorer l'adaptation à la sécheresse de la vigne est un des enjeux majeurs des prochaines années. Pour cela, une adaptation des pratiques culturales peut être proposée, en particulier le choix pertinent du matériel végétal et notamment du porte-greffe.Dans ce travail, le rôle du porte-greffe vis-à-vis de la réponse de la vigne greffée à la contrainte hydrique a été étudié, en utilisant des approches écophysiologiques, moléculaires et de modélisation. Des expériences ont été réalisées en conditions contrôlées afin d’étudier l’effet du déficit hydrique à court et long terme sur les réponses de différents porte-greffes greffés avec le même scion.Le modèle écophysiologique a démontré que les porte-greffes affectent l'ouverture stomatique du greffon par des processus coordonnés incluant les caractéristiques racinaires, les signaux hydrauliques et les signaux chimiques lors d’un déficit hydrique à court terme. La conductance stomatique, le taux de transpiration et la conductance hydraulique des feuilles ont été plus élevés en conditions irriguées et de stress hydriques modérés chez le génotype résistant à la sécheresse (110 Richter) par rapport au génotype sensible à la sécheresse (Vitis riparia cv. Gloire de Montpellier). Nous avons identifié plusieurs paramètres génétiques impliqués dans le contrôle de la régulation stomatique. Des différences d’architecture racinaire et de conductivité hydraulique des racines ont été identifiées entre les porte-greffes.Le déficit hydrique à long terme a entrainé des réponses adaptatives différentes entre les porte-greffes. Le génotype tolérant la sécheresse a induit une modification du diamètre des vaisseaux du xylème de la partie apicale de la racine en réponse au déficit hydrique modéré tandis que le génotype sensible n'a pas présenté de différence par rapport au contrôle. L’analyse transcriptomique des racines a identifié des gènes spécifiques aux différents génotypes, qui sont régulés en fonction du niveau de déficit hydrique. La comparaison entre les niveaux de stress et les génotypes a identifié 24 gènes intervenant dans l’interaction « traitement × génotype ». Ces gènes sont majoritairement impliqués dans le métabolisme des lipides et de la paroi cellulaire. Des courbes de réponse au déficit hydrique spécifiques aux différents génotypes ont été observées. La protection contre les dommages liés aux stress oxydatifs induits par le stress hydrique semble être un mécanisme important chez le porte-greffe résistant à la sécheresse. Le génotype sensible semble répondre au déficit hydrique par une modification des propriétés de la paroi cellulaire de la racine. / Climate change raises concerns about temporal and spatial water availability in many grape growing countries. The rapidly increasing world population and the scarcity of suitable land for agricultural food production, together with a changing climate, will increase competition with grape-producing areas for the use of land and resources. Consequently, other practices that can potentially improve water management of vineyards and water acquisition by grapevines need to be considered. Aside from canopy systems and their management, the choice of plant material is a key issue. Therefore, in the present work, the role of different rootstocks, regarding their tolerance to drought, was investigated for their potential effects on i) water uptake, ii) water transport and iii) shoot water use, using a combination of ecophysiological, modelling and transcriptomic approaches. Experiments were conducted under controlled conditions to decipher short and long term responses to drought of different rootstocks grafted with the same scion. An ecophysiological model was used to investigate the roles of rootstock genotypes in the control of stomatal aperture. Long-term steady state water-deficit conditions were used to examine the responses of i) whole plant growth, root anatomy and hydraulic properties and ii) transcriptome remodelling in the roots.Our model showed that rootstock affect stomatal aperture of the grafted scion via coordinated processes between root traits, hydraulic signals and chemical signals. Stomatal conductance, transpiration rate and leaf-specific hydraulic conductance were higher and better maintained under well-watered and moderate water-deficit conditions in the drought-tolerant genotype (110 Richter) compared to the drought-sensitive one (Vitis riparia cv. Gloire de Montpellier). We identified several genotype-specific parameters which play important roles, like root-related parameters, in the control of stomatal regulation. Additionally, root system architecture and root hydraulic properties are important constitutive traits identified between rootstocks.Long-term water-deficit induced genotype adaptive responses in the roots were evaluated. The drought-tolerant genotype exhibited a substantial shift in root tips xylem conduit diameter under moderate water-deficit while the drought-sensitive genotype did not respond. Transcriptomic analysis identified genotype-specific transcripts that are regulated by water-deficit levels. The comparison between stress levels and genotypes identified 24 significant genes in “treatment×genotype” interactions, most of them were involved in lipid metabolism and cell wall processes. These genes displayed genotype-specific water-deficit response curves. Protection against drought-induced oxidative damage was found to be an important mechanisms induced by the drought-tolerant rootstock, while the drought-sensitive one responds to water-deficit by modification of cell wall properties.

En Amazonie orientale, l’agriculture familiale contribue significativement à la transformation des écosystèmes forestiers en pâturages. La mise en valeur pastorale se fait généralement de manière monospécifique avec une Poacée pérenne d’origine africaine (Brachiaria brizantha cv. Marandu) qui constitue la principale offre fourragère. Mais les pratiques pastorales mises en oeuvre sur une exploitation conduisent souvent à une dégradation des pâturages, qui se manifeste par une prolifération des plantes adventices. Le pâturage a été modifié par l’introduction de deux Fabacées pérennes fourragères originaires d’Amérique Latine, l’une herbacée (Arachis pintoï cv. Amarelo) et l’autre ligneuse (Leucaena leucocephala). Pendant la saison sèche, nous avons étudié les interactions entre B. brizantha et des Fabacées fourragères implantées. Cette étude est la première approche intégrée (écophysiologie) qui étudie les caractéristiques adaptatives et les effets des Fabacées sur la capacité de résistance à la contrainte hydrique des pâturages à partir des évolutions des échanges gazeux foliaires, du potentiel hydrique et de l’état hydrique du sol. Le dispositif expérimental était composé de cinq parcelles de 100 m2 isolées du bétail correspondant à cinq traitements différents. Les trois espèces étudiées ont été cultivées seules et en association. Trois répétitions ont été réalisées pour chaque traitement afin de valider statistiquement les résultats et prendre en compte la variabilité spatiale du sol. En monoculture, les valeurs de conductances stomatiques de B. brizantha sont relativement élevées au regard des conditions climatiques par rapport à des valeurs habituelles de plantes C4 au champ alors que les valeurs d’assimilations nettes sont celles mesurées couramment. A. pintoï et L. leucocephala possèdent des valeurs de conductances stomatiques et d’assimilations mesurées habituellement sur les plantes C3 au champ. En situation de sécheresse, les trois espèces étudiées en monoculture adoptent un mouvement de fermeture stomatique 30 jours après l’arrêt des pluies et ajustent ainsi leur conductance sur l’épuisement de la réserve utile du sol. Cette stratégie permet le maintien de l’activité photosynthétique indispensable à la survie cellulaire et de maintenir une transpiration suffisante pour réguler leur température. Les trois espèces survivent par évitement de la sécheresse, en réduisant leur surface foliaire active et en fermant leurs stomates dès l’abaissement du potentiel hydrique. B. brizantha a le même comportement lorsqu’il est cultivé seul ou associé à A. pintoï que ce soit au niveau de la conductance stomatique, de l’assimilation de CO2 ou de l’efficience instantanée de l’eau. Cependant, son potentiel hydrique est affecté plus précocement au cours d’un stress hydrique lorsqu’il est en concurrence avec A. pintoï. Dans le cas de cette association, notre étude montre que la présence de B. brizantha a un effet négatif sur les activités photosynthétiques et donc sur la production de biomasse d’A. pintoï, espèce considérée pourtant comme sciaphile. Enfin, les fonctions métaboliques de B. brizantha sont réduites lorsqu’il est associé à L. leucocephala du fait de l’ombrage. L. leucocephala évite la sécheresse en réduisant sa surface foliaire. L’augmentation d’insolation en fin de saison sèche affaiblit cependant les plantes associées aux strates inférieures et réduit la quantité de fourrage disponible sur pied. Nous proposons aux agriculteurs de mettre en place une gestion durable de leurs pâturages par la création d’associations végétales fourragères adaptées aux contraintes biotiques et abiotiques. / In the Eastern Amazon region (Pará, Brazil), smallholder farming significantly contributes to the transformation of the Amazonian rain forest ecosystem into pasture land that typically includes a single species, generally a perennial fodder grass (Poaceae) originating from Africa (Brachiaria brizantha cv. Marandu). Such pastures rapidly lose their sustainability and get invaded by weeds. To prevent these effects, two imported perennial fodder species of the Fabaceae family (Arachis pintoï cv. Amarelo and Leucaena leucocephala Lam.) have been mixed with the African grass Brachiaria and the interrelations between B. brizantha and the Fabaceae species have been studied. In this unique ecophysiological study, plant parameters, such as gas exchange and plant water potential have been correlated with soil parameters, such as soil water content. The final goal was to assess the impact of the Fabaceae plants on pasture tolerance to water deficit. The experimental setting included five treatments applied to 100 m2 fenced plots to keep cattle away. Treatments corresponded to various combinations between the grass and the two Fabaceae species. Three biological repeats were set up for each treatment for statistical significance and in order to account for soil structure variability. In monospecific plots, B. brizantha exhibited stomatal conductance values higher than those expected from typical C4 species whereas net CO2 assimilation rates were normal. A. pintoï and L. leucocephala had usual stomatal conductance values for field-cultivated C3 plants. In response to drought, a general adjustment in stomatal conductance was observed 30 days into the dry season (i.e. without rain), suggesting that the plants limited transpiration rates according to the progressive decrease in soil water content. This strategy allowed them to maintain photosynthetic activities and to supply photosynthates to their tissues while limiting rises in temperatures. Upon exhaustion of soil water cotent, decreases in leaf water potentials were observed and plants escaped drought by reducing their leaf area and by abruptly closing their stomata. Brachiaria’s responses to drought were similar in mixed and monospecific plots regarding stomatal conductance, net CO2 assimilation rate or real-time water efficiency. However, when grown in mixed plots with A. pintoï, Brachiaria’s leaf water potential decreased rapidly after the onset of drought, due to the competition for water. In a A. pintoï ! Brachiaria plot, Brachiaria had a negative impact on A. pintoï photosynthetic activities and biomass production, even though the latter was considered as a shade plant species. On the other hand, Brachiaria metabolic activities were reduced in L. leucocephala ! Brachiaria combinations, due to the interception of light supply by L. leucocephala. L. leucocephala avoided water deficit by reducing leaf area. The resulting increase in light intensity reaching the lower strata, toward the end of the dry season weakened the shortest plants and limited fodder production. In conclusion, we propose that farmers implement pasture sustainability by developing crop mixing, using fodder species adapted to abiotic stresses. Furthermore, our results show that several crop combinations represent viable solutions to the perpetuation of new pastures. Each fodder species presents specific drought adaptation features. Combining them could be beneficial if pastoral pressure was allowed to develop according to the plants tolerance level. Improvements in fodder production and diversity could extend the life-span of smallholder settlements and as a result slow down deforestation

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The difference in rainfall throughout the year is a recurring problem that the plants in the field must contend as a result of the moments of drought to which they can be submitted. In the Caatinga, this problem is even greater, since the rains are very sparse and irregular, causing drought for months. The plants of the Caatinga have several adaptations to resist such conditions. This work aimed to evaluate physiological parameters of two endemic species of the Caatinga, the |catingueira| (Poincianella pyramidalis) and |pinhão-bravo| (Jatropha mollissima), in search to discover what strategies these species adopt to survive the drought. Two collections, one in the dry season and one in the wet, were made to evaluate parameters of water relations, concentrations of organic solutes and photosynthetic pigments, chlorophyll a fluorescence and gas exchange. The |catingueira| shown to have been damaged by drought, with a significant reduction in their rates of water relations, particularly in the relative water content, which reached values below 60%, and the performance indices of chlorophyll a fluorescence. The |pinhão-bravo| was able to maintain their high tissue turgor, but the rates of fluorescence and net photosynthesis demonstrated that he was affected by drought since their photosynthetic parameters suffered very significant reductions. / A diferença de precipitação ao longo do ano é um problema recorrente que as plantas em campo precisam enfrentar, em decorrência dos momentos de déficit hídrico aos quais elas podem ser submetidas. Na Caatinga, esse problema é ainda maior, já que as chuvas são muito esparsas e irregulares, ocasionando meses a fio de estiagem. As plantas da Caatinga possuem diversas adaptações para suportar tais condições. Esse trabalho teve por objetivo avaliar parâmetros fisiológicos de duas espécies endêmicas da Caatinga, a catingueira (Poincianella pyramidalis) e o pinhão-bravo (Jatropha mollissima), em busca de descobrir que estratégias essas espécies adotam para sobreviver ao período de estiagem. Foram feitas duas coletas, uma na estação seca e outra na chuvosa, para avaliar parâmetros de relações hídricas, concentrações de solutos orgânicos e de pigmentos fotossintéticos, fluorescência de clorofila a e trocas gasosas. A catingueira demonstrou ter sido bastante afetada pela seca, com redução significativa nos seus parâmetros de relações hídricas, sobretudo no teor relativo de água, que atingiu valores abaixo de 60%, e nos índices de desempenho da fluorescência da clorofila a. O pinhão-bravo conseguiu manter a turgescência de seus tecidos alta, mas os índices da fluorescência e da fotossíntese líquida demonstraram que ele também foi afetado pelo déficit hídrico, uma vez que seus parâmetros fotossintéticos sofreram reduções bastante significativas.

INTRODUÇÃO: A aspiração traqueal (ASP) é um procedimento de rotina em pacientes sob ventilação mecânica, porém em algumas situações pode não ser eficiente. Como adjuvante usa-se a técnica \"Bag-Squeezing\" (BS) que consiste na hiperinflação manual associada à compressão torácica manual expiratória seguida ASP. Embora efetiva esta técnica pode apresentar algumas limitações como a desconexão do ventilador mecânico, além do controle precário do pico de pressão inspiratória (PPI) e pico de fluxo inspiratório (PFI). Como opção, podemos substituir o ressuscitador manual pelo próprio ventilador mecânico, alterando seus parâmetros e evitando assim a desconexão. Propusemos padronizar esta técnica e denominá-la PEEP-ZEEP (PZ); realizando-se a inflação dos pulmões aumentando a PEEP em 10 cmH2O, por 5 ciclos respiratórios, seguido de rápida descompressão pulmonar pela redução abrupta da PEEP até 0 cmH20, simultâneo à compressão torácica manual. OBJETIVOS: Avaliar o comportamento hemodinâmico, da troca gasosa e da mecânica respiratória, na aplicação das técnicas ASP, BS e PZ e seus efeitos na remoção de secreções brônquicas em pacientes ventilados mecanicamente. MÉTODO: 1ª etapa - \"Pacientes sem secreção brônquica\" estudamos prospectivamente 45 pacientes, divididos aleatoriamente em 3 grupos iguais, avaliamos os efeitos da aplicação das técnicas ASP, BS e PZ nos parâmetros hemodinâmicos, na troca gasosa e na mecânica pulmonar antes, imediatamente após, do 1o ao 10o e 30o min. subseqüentemente à aplicação das técnicas. Na 2ª etapa - \"Pacientes com hipersecreção brônquica\" foram estudados prospectivamente 15 pacientes ventilados mecanicamente, que apresentavam hipersecreção brônquica submetidos às técnicas ASP, BS e PZ aleatoriamente em intervalos de 2 horas, avaliamos as mesmas variáveis da 1a etapa porém acompanhamos os pacientes até 120 min. após cada intervenção. Avaliamos também o peso úmido da secreção brônquica, bem como sua reologia. RESULTADOS: 1ª etapa - Semelhantes quanto aos dados antropométricos e tempos de CEC, nossos pacientes apresentavam 59±10anos, IMC 26±3,2 kg/m2 e tempo médio de CEC de 91±19min. Houve elevação da FC somente após aplicação de BS (98±8; 106±10). PAM e SpO2 não se alteraram, observamos elevação na ETCO2 (36±6; 37±6 e 37±7; 39±8) nas técnicas BS e PZ respectivamente. Não verificamos alteração na mecânica respiratória até 30 min. após aplicação das técnicas. Durante a execução das técnicas BS e PZ respectivamente observamos elevação significante do PPI (63±17 vs 17±3), PPLATÔ (22±5 vs 26±3), PFI (154±27 vs 20±5) e PFE (86±20 vs 64±10). 2ª etapa - Nossos pacientes apresentavam 66±14anos, IMC 24±3,2 kg/m2 e tempo médio de CEC de 113±54min. A FC e a SpO2 não se alteraram, porém houve elevação significante da PAM imediatamente após a aplicação de ASP, BS e PZ (85±12 vs 101±16, 90±12 vs 100±14, 84±10 vs 97±11). Na PZ houve diminuição na ETCO2 (36±6 vs 35±7). Não observamos alteração na mecânica respiratória até 120 min. após aplicação das técnicas. Durante a execução das técnicas BS e PZ respectivamente observamos elevação significante do PPI (45±22 vs 27±3) e PFI (91±21 vs 44±17), porém a PPLATÔ (27±15 vs 26±3) e o PFE (71±20 vs 64±13) foram semelhantes entre elas. Não encontramos diferença significante no peso úmido do muco ASP(0,91±1), BS(1,09±1) e PZ(0,53±0,5), nem na análise do deslocamento e da viscoelasticidade. CONCLUSÕES: As técnicas não alteraram significantemente o comportamento hemodinâmico, de troca gasosa e de mecânica respiratória. BS e PZ foram capazes de aumentar o PFE, porém a nova proposta PZ permite maior controle das variáveis de mecânica respiratória, possibilitando monitoramento das pressões e fluxos impostos ao sistema respiratório. Todas as técnicas foram capazes de remover secreções brônquicas de forma semelhante. / INTRODUCTION: Tracheal suction (TS) is a routine procedure in patients submitted to mechanical ventilation. In association, the bag-squeezing (BS) technique is described as a manual hyperinflation associated to a manually assisted coughing followed by TS. This technique might present few limitations as its mechanical ventilator disconnection and poor control of variables such as peak inspiratory pressure (PIP) and peak inspiratory flow (PIF). We might substitute the manual ressuscitator by the mechanical ventilator itself altering its parameters and avoiding its disconnection. We proposed to standardize this technique and named it PEEP-ZEEP (PZ); inflate the lungs increasing the PEEP in 10 cmH20, trough 5 respiratory cycles, followed by an abrupt pulmonary decompression bringing the PEEP to 0 cmH20, associated to the manually assisted coughing. OBJECTIVES: Assess the hemodynamic, gas exchange and respiratory mechanics variables during the use of TS, BS and PZ techniques and assess their effects in the removal of bronchial secretions in mechanically ventilated patients. METHODS: First step - \"Patients without bronchial secretions\" - We assessed 45 patients prospectively, divided randomically into three groups, evaluating the effects of TS, BS and PZ techniques in the haemodynamics, gas exchange and respiratory mechanics variables before, immediately after, in the 10th and 30th minute after the technique. Second step - \"Patients with bronchial secretions\" - We assessed 15 mechanically ventilated patients submitted to the TS, BS and PZ techniques within 2 hours, evaluating the same variables of the first step. However we followed-up the patients until 120 minutes in each technique. We also assessed the humid weight of the bronchial secretions as well as the mucus reology. RESULTS: Results were similar when related to antropometric data and ECC period. First step - There was a raise in the HR after the BS procedure (98±8; 106±10), MAP and SpO2 did not altered. Raise in ETCO2 (36±6; 37±6 and 37±7; 39±8) in the BS e PZ techniques respectively, without alteration in the respiratory mechanics until 30 minutes after the techniques. During the BS e PZ techniques, we observed a significant increase in PIP (63±17 vs 17±3), PPLATEU (22±5 vs 26±3), PIF (154±27 vs 20±5) and PEF (86±20 vs 64±10). Second step - HR and SpO2 did not altered, there was a significant increase in MAP immediately after the TS, BS and PZ techniques (85±12 vs 101±16, 90±12 vs 100±14, 84±10 vs 97±11). The PZ technique had lower ETCO2 (36±6 vs 35±7). We did not observed any respiratory mechanics alteration until 120 minutes after the techniques. During the BS e PZ techniques, respectively, we observed an increase in the PIP (45±22 vs 27±3) and PIF (91±21 vs 44±17), however the PPLATEU (27±15 vs 26±3) and PEF (71±20 vs 64±13) were similar. The PZ technique (0,54±0,5) remove less humid weight mucus when compared to TS (0,91±1) and BS (1,09±1), but the analysis by simulated cough machine PZ (25?11) was better then TS(33?13). CONCLUSION: All techniques remove bronchial secretions and did not altered the hemodynamic, gas exchange and respiratory mechanics significantly. BS and PZ were able to enhance the PEF, however the new proposition of the PZ technique allows a better control of the respiratory mechanics variables.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O presente trabalho teve por objetivo estudar as respostas fisiolÃgicas e bioquÃmicas de plÃntulas de cajueiro anÃo-precoce (Anacardium occidentale L.) à salinidade em duas condiÃÃes ambientais de cultivo. Para isso, as plÃntulas foram cultivadas em vasos de polietileno contendo somente soluÃÃo nutritiva (tratamento controle) ou soluÃÃo nutritiva com NaCl a 50, 100, 150 e 200 mM (tratamentos salinos), sendo mantidas em duas condiÃÃes ambientais: casa de vegetaÃÃo e sala de germinaÃÃo. Os efeitos do estresse salino foram avaliados atravÃs de medidas de crescimento, trocas gasosas, teores de clorofila, potencial osmÃtico foliar e teores de solutos orgÃnicos (prolina, N-aminossolÃveis e carboidratos solÃveis) e inorgÃnicos (Na+, Cl- e K+) nas folhas e raÃzes. TambÃm foram estudadas as alteraÃÃes na expressÃo gÃnica com a salinidade, o que foi feito atravÃs da comparaÃÃo dos padrÃes eletroforÃticos 2D das proteÃnas de folhas e raÃzes. A salinidade reduziu o crescimento das plÃntulas em ambas as condiÃÃes ambientais de cultivo, sendo que nas plÃntulas da casa de vegetaÃÃo, a inibiÃÃo do crescimento foi mais acentuada do que naquelas da sala de germinaÃÃo. Este fato correlacionou-se com as maiores reduÃÃes na fotossÃntese lÃquida, na transpiraÃÃo e na condutÃncia estomÃtica das plÃntulas da casa de vegetaÃÃo em relaÃÃo Ãs da sala de germinaÃÃo. Nas duas condiÃÃes de cultivo, os efeitos inibitÃrios do NaCl foram mais conspÃcuos nas raÃzes do que na parte aÃrea. A salinidade nÃo causou grandes mudanÃas nas concentraÃÃes internas de CO2 das plÃntulas de cajueiro, sugerindo a participaÃÃo de fatores nÃo-estomÃticos na inibiÃÃo das taxas fotossintÃticas. Os teores foliares de clorofila a, b e total foram influenciados pela salinidade e pelas condiÃÃes de cultivo das plÃntulas, sendo que as da sala de germinaÃÃo apresentaram os maiores conteÃdos e as menores reduÃÃes desses pigmentos devido à salinidade. As leituras feitas com o medidor portÃtil de clorofila, SPAD-502, correlacionaram-se positivamente com os teores foliares de clorofila, expressos em g.cm-2, tanto nas plÃntulas da casa de vegetaÃÃo quanto nas da sala de germinaÃÃo. As maiores reduÃÃes no potencial osmÃtico e os maiores acÃmulos de Na+ e Cl- nas folhas pela salinidade, em relaÃÃo ao controle, foram observados nas plÃntulas da casa de vegetaÃÃo. Por outro lado, os teores de K+ nesse ÃrgÃo nÃo diferiram muito entre as duas condiÃÃes de cultivo empregadas. As raÃzes acumularam grandes quantidades de Na+ e Cl- em seus tecidos, as quais foram acompanhadas de grandes decrÃscimos nos teores de K+, em ambas as condiÃÃes de cultivo. Com o aumento da salinidade, os teores de prolina foram aumentados, principalmente nas folhas, sendo os maiores incrementos observados nas plÃntulas da casa de vegetaÃÃo. Os teores de carboidratos solÃveis foram aumentados e reduzidos, devido à salinidade, somente nas folhas das plÃntulas da sala de germinaÃÃo e nas raÃzes das plÃntulas da casa de vegetaÃÃo, respectivamente. Nas duas condiÃÃes de cultivo, a salinidade aumentou os teores de N-aminossolÃveis nas folhas e nas raÃzes das plÃntulas de cajueiro. O padrÃo de expressÃo gÃnica das folhas e das raÃzes foi alterado pelo estresse salino em ambas as condiÃÃes ambientais. A salinidade causou aumentos e diminuiÃÃes nas taxas de expressÃo de vÃrias proteÃnas, sendo que algumas desapareceram completamente e outras foram aparentemente sintetizadas de novo nas plÃntulas estressadas. As proteÃnas diferencialmente reguladas pelo estresse salino foram bastante diferentes nas duas condiÃÃes ambientais empregadas. Faz-se necessÃrio o seqÃenciamento e a identificaÃÃo dessas proteÃnas para que se possa especular sobre seus possÃveis papÃis no processo de aclimataÃÃo das plÃntulas de cajueiro Ãs condiÃÃes de salinidade. / Early-dwarf cashew seedlings (Anacardium occidentale L.) were used in order to investigate the physiological and biochemical changes induced by salt stress in two environmental conditions. The seedlings were cultivated in plastics pots containing only nutrient solution (control treatment) or nutrient solution with NaCl at 50, 100, 150 and 200 mM (saline treatment). They were kept in two environmental conditions: greenhouse and growth room. The effects of salinity on the growth, gas exchange, chlorophyll content, osmotic potential and organic (proline, soluble amino-N, soluble carbohydrates) and inorganic (Na+, Cl-, K+) solute contents from both leaves and roots were studied. Salt stress induced changes in gene expression were studied both in leaves and roots comparing 2D electrophoretic pattern. Salinity inhibited the growth of seedlings in both environmental conditions, being the reduction in seedlings growth in the greenhouse more conspicuous than those cultivated in the growth room. This fact was correlated with highest reductions in net photosynthetic rate, in transpiration and stomatal conductance of seedlings grown in the greenhouse when compared with those of growth room. In both cultivation conditions, the root growth was affected by NaCl than shoot growth. The salinity stress not caused great changes in CO2 internal concentration, suggesting that the inhibition of photosynthesis also may be attributed to non-stomatal factors. Leaf chlorophyll a, b and total contents were influenced by salinity and environmental conditions, being observed the highest contents and the lowest reductions of these pigments due to salinity in seedlings under growth room conditions. The readings of portable chlorophyll meter, SPAD-502, were positively correlated to leaf chlorophyll contents, expressed in g.cm-2, both in greenhouse and growth room conditions. In the salt stress conditions, the higher reductions of osmotic potential and higher Na+ and Cl- accumulations in leaves were observed in seedlings grown in the greenhouse. On the other hand, leaves K+ contents did not differ much among the cultivation conditions used. The roots accumulated greater amounts of Na+ and Cl- in their tissues, which were accompanied of great decreases in the K+ contents in both cultivation conditions. Proline content increased with the increase in salt stress especially in leaves, being the greater increases observed in seedlings cultivated in the greenhouse. The soluble carbohydrates contents were increased and decreased, due to salinity, only in leaves of seedlings of growth room and roots of those grown in the greenhouse, respectively. In both cultivation conditions, salinity increased the leaf and root soluble amino-N contents of cashew seedlings. The gene expression patterns both leaves and roots were altered by salt stress, in both environmental conditions. Salinity induced increases and decreases in expression of various proteins, being that some proteins disappeared completely and other were apparently synthesized de novo in the seedlings stressed. The proteins differentially regulated by salt stress were enough different among the environmental conditions used. Future studies should be focused on sequencing and identification of proteins whose rate of synthesis varied as a result of salinity, in order to better characterize their possible roles in the process of acclimation of cashew seedlings to salinity conditions

Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. The first experiment served as the foundation for this dissertation and was designed to quantify tradeoffs associated with delaying forest establishment activities by introducing a fallow year in order to provide longer-term management of competing vegetation. A range of six operationally relevant treatments were applied over two growing seasons that included in the first (1) a no-action control, (2) a spring release only, (3) a fall site preparation without sulfometuron methyl followed by a spring release, as well as (4) a fall site preparation with sulfometuron methyl and a spring release. In the second year, there was (5) a fall site preparation without sulfometuron methyl followed by a spring release and also in the second year (6) a fall site preparation with sulfometuron methyl and a spring release. Treatments 5 and 6 were left fallow without planting during the first year. These treatments were applied in two replicated experiments within the Oregon Coast Range. After adjusting for initial seedling size, year-3 results indicated that plantation establishment and competition control immediately after harvest (i.e. no fallow period) enabled seedlings to be physically larger than those planted after a one year delay. At the Boot study site, limiting vegetation below 20% for the first growing season improved year-3 Douglas-fir seedling stem volume over 273 cm³. Delaying establishment activities one year and reducing competing vegetation below 11% enabled seedling volume after two years to be statistically the same as three year old seedlings in the no-action control, a volume range of between 148 to 166 cm³. Delaying forest establishment at Jackson Mast improved seedling survivorship over 88% when a spring heat event reduced survivorship of trees planted a year earlier to less than 69%. The combined effect of applying a fall site preparation and spring release was necessary to reduce competitive cover below 10% in the year following treatment and provided longer-lasting control of woody/semi-woody plants. Less intense control measures (i.e. no-action control and treatment 2) were not able to restrain woody/semi-woody plant cover which grew to nearly 40% at Boot and over 24% at Jackson Mast in three years. No treatment regime provided multi-year control of herbaceous species. Including sulfometuron methyl in the fall site preparation tank-mix did not have a negative effect on seedling growth or provide significant reductions in plant community abundance in the year following application when compared to similar regimes that did not include the chemical. Delaying establishment lengthened the amount of time associated with forest regeneration except on a site that accentuated a spring heat event. In the second study, horizontal distance and azimuth readings provided by a ground-based laser were used to stem map seedling locations and experimental unit features at Boot. These data were used to create a relative Cartesian coordinate system that defined spatially explicit polygons enabling, for the first time, the ability to collect positional data on competing forest vegetation within an entire experimental unit. Deemed "vixels" or vegetation pixels, these polygons were assessed for measures of total cover and cover of the top three most abundance species during the initial three years of establishment. An alternate validity check of research protocols was provided when total cover resulting from this vixel technique was compared to a more traditional survey of four randomly located subplots. The resulting linear regression equation had an adjusted R² of 0.90 between these two techniques of assessing total cover. When compared within a treatment and year, total cover differed by less than 12 percentage points between the two techniques. Analysis of year-3 woody/semi-woody plant cover produced by the techniques led to identical treatment differences. Two treatments resulted in woody/semi-woody cover of approximately 1500 ft² by the vixel method and nearly 40% cover by the subplot method while the remaining four treatments were grouped below 600 ft² or 20% cover, respectively. With continued refinement, these techniques could visually present forest development through all phases and provide long-term information used to bolster growth and yield models, measures of site productivity, as well as community ecology research. The third study evaluated the season-long gas exchange and biomass partitioning of four weedy plant species capable of rapidly colonizing Pacific Northwest regenerating forests. Cirsium arvense, Cirsium vulgare, Rubus ursinus and Senecio sylvaticus were studied at two sites. A greenhouse was used to introduce two levels of irrigation (well-watered and droughty). These species were also studied while growing among a larger vegetation community at a field site. Irrigation treatments had little impact on gas exchange rates. Species achieved maximum photosynthetic rates of 30, 20, 15 and 25 μmol CO₂ m⁻² s⁻¹ (respectively) prior to mid-July coinciding with an active phase of vegetative growth. As the season progressed, photosynthetic rates declined in spite of well-watered conditions while transpiration rates remained relatively consistent even when soil water decreased below 0.25 m³ H₂O/m³ soil. Water use efficiency was high until late-July for all study species, after which time it decreased below 5 μmol CO₂ · mmol H₂O⁻¹. Multi-leaf gas exchange measurements as well as biomass data provided a holistic view of plantlevel mechanisms used to shunt activity toward developing tissues. Herbaceous species had assimilation rates that differed vertically (within each species) by as much as 10 to 20 μmol CO₂ m⁻² s⁻¹ from July to September as lower leaves senesced in favor of those higher on study plants. Specific leaf area was greatest in June for all species then declined indicating species placed little effort into sacrificial early season leaves when compared to those higher on the plant that could continue to support flowering or vegetative growth. The study of seasonal gas exchange in the presence of declining water availability has helped to describe competitive mechanisms at work during forest regeneration as well as provide physiologic support for the application of vegetation management regimes. / Graduation date: 2013

In the studies underlying this thesis, various source tracing techniques were applied to environmental samples from the Baltic region. Comprehensive sampling and analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surface sediments in Swedish coastal and offshore areas resulted in a unique data set for this region. Nearly 150 samples of surface sediments were analyzed for all tetra- to octa-chlorinated PCDD/Fs. The levels showed large spatial variability with hotspots in several coastal regions. Neither Sweden nor the EU has introduced guideline values for PCDD/Fs in sediment, but comparisons to available guidelines and quality standards from other countries indicate that large areas of primarily coastal sediments may constitute a risk to marine organisms. Multivariate pattern analysis techniques and receptor models, such as Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF), were used to trace sources. These analyses suggested that three to six source types can explain most of the observed pattern variations found in the sediment samples. Atmospheric deposition was suggested as the most important source to offshore areas, thus confirming earlier estimates. However, spatial differences indicated a larger fraction of local/regional atmospheric sources, characterized by PCDFs, in the south. This was indicated by the identification of several patterns of atmospheric origin. In coastal areas, the influence of direct emission sources was larger, and among these, chlorophenol used for wood preservation and emissions from pulp/paper production and other wood related industry appeared to be most important. The historic emissions connected to processes involving chemical reactions with chlorine (e.g. pulp bleaching) were found to be of less importance except at some coastal sites. The analysis of PCDD/Fs in Baltic herring also revealed spatial variations in the levels and pollution patterns along the coast. The geographical match against areas with elevated sediment levels indicated that transfer from sediments via water to organisms was one possible explanation. Fugacity, a concept used to predict the net transport direction between environmental matrices, was used to explore the gas exchange of hexachlorocyclohexanes (HCHs) and polychlorinated biphenyls (PCBs) between air and water. These estimates suggested that, in the Kattegat Sea, the gaseous exchange of HCHs primarily resulted in net deposition while PCBs were net volatilized under certain environmental conditions. The study also indicated that, while the air concentrations of both PCBs and γ-HCH are mostly dependent upon the origin of the air mass, the fluctuations in α-HCH were primarily influenced by seasonal changes.

During photosynthesis Plantaginaceae species can produce glucose derivatives such as iridoid glycosides and alcohol sugars that in addition to sucrose can be exported from leaves. Plantago lanceolata transported sorbitol in addition to sucrose especially at warmer leaf temperatures. However, two iridoids, catalpol and aucubin, found in P. lanceolata were not readily labelled from 14CO2 under any conditions examined. In contrast, in two greenhouse, cut-flower cultivars of Antirrhinum majus the iridoids, antirrhinoside and antirrhide, were readily 14C-labelled along with sucrose but little 14C was recovered in alcohol sugars (e.g., mannitol). The amount of 14C-partitioned into antirrhinoside increased at higher temperatures. Exposing leaves of P. lanceolata and A. majus to reduced-photorespiratory conditions (e.g. short-term CO2 enrichment and/or low O2) increased fixation and export. Under low O2 in P. lanceolata sorbitol 14C-labelling increased relative to sucrose and in A. majus 14C-labelling of sucrose increased relative to antirrhinoside. Also 14C-labelling of antirrhide increased more than antirrhinoside. During both short-term and long-term acclimation to high CO2, whole plant NCER, leaf photosynthesis and export increased in A. majus. Taken together the temperature and CO2 enrichment studies show plasticity in Plantaginaceae species to synthesize and transport sucrose and auxiliary glucose esters and alcohol sugars in a species-specific manner (depending on the rate of carboxylation).