Plant embolism : new techniques of measurements and the relationship with the xylem lignification

Orientador: Paulo MazzaferaTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A formação de bolhas - embolia - nos conduítes do xilema tem ganho crescente interesse científico, considerando sua importância nas estratégias de plantas na resistência à seca. No entanto, continua a ser desconhecida a forma como os componentes químicos das paredes dos conduítes estão relacionados com a resistência à embolia. A lignina, o segundo composto mais abundante nas plantas depois da celulose, é essencial para o transporte de água e deve ter algum papel na resistência à embolia. A essência do presente trabalho foi criar condições (estabelecer métodos) e apontar evidências de que o conteúdo e/ou tipos de lignina estão relacionados com a resistência à embolia. A estimativa correta da embolia tem sido um desafio, principalmente devido à alta tensão nos conduítes e às estruturas microscópicas ou nanoscópicas do sistema de transporte de água, além dos artefatos em que os métodos disponíveis estão propensos. Assim, nos capítulos 1 e 2 são apresentados novos métodos e aparatos para se estudar o sistema hidráulico de plantas, procurando principalmente eliminar os artefatos que os métodos disponíveis possuem. No capítulo 1: "A low cost apparatus for measuring the xylem hydraulic conductance in plants", publicado em Bragantia, foi descrita a montagem de um aparato e a sua calibração, bem como adaptações de baixo custo que tornam o equipamento acessível. O aparato permite medir a condutância em partes de raízes ou ramos, ou em todo o sistema, no caso de pequenas plantas ou mudas. O aparato também pode ser utilizado para se estimar embolia. No capítulo 2: "Plant pneumatics: stem air flow is related to embolism ¿ new perspectives on methods in plant hydraulics", publicado em New Phytologist, nós descrevemos um novo método para se estimar embolia, baseado em medições de fluxo de ar de ramos inteiros. Para calcular a quantidade de ar que flui para fora do ramo, um vácuo é aplicado aos ramos cortados, que são submetidos à diferentes potenciais hídricos. Propusemos um novo método para se estimar embolia, que é simples, eficaz, rápido e barato e permite várias medições no mesmo ramo, abrindo novas possibilidades para se estudar hidráulica de plantas. No capítulo 3: "Is embolism resistance in plant xylem associated with quantity and characteristics of lignin?", nós sugerimos que há relação entre conteúdo de lignina na madeira e resistência ao embolismo. Para chegar a isto, reunimos dados de conteúdo total de lignina na madeira e potencial de água em que 50% da condutividade no xilema de 99 espécies. Essas análises indicam uma relação limítrofe entre a resistência à embolia e o conteúdo de lignina. Nossas conclusões são que espécies com baixo conteúdo de lignina parecem ser mais vulneráveis à embolia, ao passo que espécies com maior conteúdo demonstram grande variabilidade de resistência. A lignina pode desempenhar algum papel indireto na resistência à embolia, uma vez que o maior conteúdo total de lignina está relacionado com paredes celulares mais espessas. Discutimos também neste capítulo, funções de diferentes tipos de lignina, diferenciando gimnospermas e angiospermas, e o desempenho de plantas transgênicas (com teor de lignina modificado) e sua relação com a vulnerabilidade à embolia. Os aparatos e os métodos aqui descritos, além das análises dos dados de literatura, permitirão futuros estudos experimentais para confirmar os modelos sobre lignina e embolia aqui propostosAbstract: Embolism formation in the xylem conduits has gained increased interest, considering its importance on the strategies of drought resistance in plants. However, remains unknown how the chemical components of conduits wall are related to embolism resistance. The lignin, the second most abundant compound of the plants, is essential to water transport and must have some role in the embolism resistance. The main objective of the present work was to evaluate whether content and/or types of lignin are related to embolism resistance. However, the correct estimative o embolism has been a challenge, mainly due to the high tension in xylem conduits and the microscopic or nanoscopic structures of water transport system, and the available methods are prone to several artifacts. Thus, in the chapter 1 and 2 we developed apparatus and methods as alternatives to study plant hydraulics. In the chapter 1: "A low cost apparatus for measuring the xylem hydraulic conductance in plants" we described the assembling of an apparatus and its calibration, as well as low cost adaptations that make the equipment accessible. The apparatus allows measuring the conductance in parts of roots or shoots, or in the whole system, in the case of small plants or seedlings. The apparatus can also be used to estimate embolism formation. In the chapter 2: "Plant pneumatics: stem air flow is related to embolism ¿ new perspectives on methods in plant hydraulics", we describe a new method for estimating estimate embolisms that is based on air flow measurements of entire branches. To calculate the amount of air flowing out of the branch, a vacuum was applied to the cut bases of branches under different water potentials. We proposed a new embolism-measurement method that is simple, effective, rapid, and inexpensive and allows several measurements on the same branch, opening new possibilities to study plant hydraulic. In the chapter 3: "Is embolism resistance in plant xylem associated with more, less, or different types of lignin?", we suggest, based on data available for lignin content and ?50 (the water potential when 50% of conductivity in the xylem is lost), a boundary relationship between embolism resistance and lignin content across various groups of seed plants. Species with low lignin content seem to be more vulnerable to embolism, whereas species with higher content show wide variability in embolism resistance. Lignin content may play some indirect role in the embolism resistance, since higher total lignin content is related to thicker cell walls. We also discuss several possible functions of lignin with different composition between gymnosperms and angiosperms and the performance of transgenic plants with modified lignin content and composition regarding vulnerability to embolism. The apparatus and methods here described and the analysis from literature data will allow further experimental studies to confirm the models of lignin and embolism here proposedDoutoradoBiologia VegetalDoutor em Biologia Vegeta

Avaliação morfologica, funcional e sensorial do sistema mastigatorio

Orientador: Maria Beatriz Duarte GaviãoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo do presente trabalho foi avaliar as características morfológicas, funcionais e sensoriais do sistema mastigatório de crianças, adolescentes e adultos. Na avaliação das características morfológicas as seguintes variáveis foram consideradas: espessura muscular através da ultra-sonografia, dimensões craniofaciais através de telerradiografias laterais, estágio da dentição (mista ou permanente). Na avaliação funcional as variáveis consideradas foram: sinais e sintomas de disfunção temporomandibular, força de mordida, eletromiografia dos músculos masseter e temporal e influência de fluidos adicionais na mastigação de alimentos sólidos naturais na deglutição. Na avaliação sensorial, atributos dos alimentos foram avaliados através de questionário específico. Verificou-se que a espessura dos músculos masseter e temporal anterior não se correlacionou com a atividade elétrica, entretanto as variáveis corporais peso e altura foram de influência, bem como o padrão facial. Sinais e sintomas de disfunção temporomandibular estiveram associados a uma tendência de ¿face longa¿, mas não foi possível a identificação de traço previsor de disfunção. A força de mordida aumentou da dentição mista para a permanente e a presença de sinais e sintomas de disfunção, principalmente aqueles relacionados à sensibilidade muscular, estiveram associados a uma diminuição na força de mordida no sexo feminino na dentição permanente, mas não na dentição mista. Na avaliação da mastigação, a adição de fluidos ao processo mastigatório influenciou a atividade elétrica e número de ciclos mastigatórios bem como a percepção sensorial principalmente para alimentos secos. O tipo de alimento teve maior efeito que a adição de fluidosAbstract: The aim of this study was to evaluate the morphological, functional and sensorial characteristics of the stomatognatic system in children, adolescents and adults. To evaluate the morphology, the following variables were considered: muscle thickness using ultrasonography, craniofacial dimensions using lateral cephalograms, dentition phase (mixed and permanent dentition). Signs and symptoms of temporomandibular dysfunction, bite force, electromyography of masseter and anterior temporalis and the influence of additional fluids on the swallowing threshold were evaluated as part of the functional exams. In the sensorial evaluation, the perception of attributes during chewing of natural solid food was assessed by a specific questionnaire. It was observed that the masseter and anterior temporalis thickness was not associated to muscle activity. However, the body variables weight and height and facial morphology as well, influenced the muscle thickness. Signs and symptoms of temporomandibular dysfunction were associated to a ¿long face¿ pattern, although it was not possible to identify any predictive trace of dysfunction. Bite force increased from mixed to permanent dentition and the presence of signs and symptoms, specially those related to muscle tenderness, was correlated to a decrease in the bite force for females in the permanent dentition only. In the mastication experiments, the added fluids influenced the electrical activity and number of chewing cycles and sensorial perception as well specially for dry food. The type of food had a larger effect than the additional fluidsDoutoradoFisiologia OralDoutor em Odontologi

Institutions and growth: a developing country case study

The Brazilian municipalities show an enormous inequality on its development level. Even within the states considered relatively prosperous, there are huge internal disparities on income levels. The richest Brazilian municipality's GDP per capita is about 190 times greater than the poorest municipality's, according to IBGE (2000) database. A possible explanation for this phenomenon relies on institutional theory. Many theoretical and empirical studies, mainly based on cross-country data, emphasize the role played by institutions on the determination of long run development. Nevertheless, there still is little research concerning the income differences within the national territory and its connection to institutional quality. The literature points out that institutions matter for the level of economic development because of their effects on political power distribution, generation of economic opportunities, innovation, human capital accumulation, and so on. Based on this assumption, the present study main goal is to analyze the effects of Brazilian municipalities' institutional quality on their GDP per capita levels. The results indicate that institutions are relevant and its importance is greater for large municipalities. On the other hand, human capital human capital is more important to small municipalities. To address the endogeneity problem inherent to the relationship between institutions and development, we employ the 2SLS method.institutions, income level, brazilian municipalities

Tomographic Image Reconstruction of Fan-Beam Projections with Equidistant Detectors using Partially Connected Neural Networks

We present a neural network approach for tomographic imaging problem using interpolation methods and fan-beam projections. This approach uses a partially connected neural network especially assembled for solving tomographic\ud reconstruction with no need of training. We extended the calculations to perform reconstruction with interpolation and to allow tomography of fan-beam geometry. The main goal is to aggregate speed while maintaining or improving the quality of the tomographic reconstruction process

Old and new calcimimetics for treatment of secondary hyperparathyroidism: impact on biochemical and relevant clinical outcomes.

Secondary hyperparathyroidism (SHPT) is associated with increased bone turnover, risk of fractures, vascular calcifications, and cardiovascular and all-cause mortality. The classical treatment for SHPT includes active vitamin D compounds and phosphate binders. However, achieving the optimal laboratory targets is often difficult because vitamin D sterols suppress parathyroid hormone (PTH) secretion, while also promoting calcium and phosphate intestinal absorption. Calcimimetics increase the sensitivity of the calcium-sensing receptor, so that even with lower levels of extracellular calcium a signal can still exist, leading to a decrease of the set-point for systemic calcium homeostasis. This enables a decrease in plasma PTH levels and, consequently, of calcium levels. Cinacalcet was the first calcimimetic to be approved for clinical use. More than 10 years since its approval, cinacalcet has been demonstrated to effectively reduce PTH and improve biochemical control of mineral and bone disorders in chronic kidney patients. Three randomized controlled trials have analysed the effects of treatment with cinacalcet on hard clinical outcomes such as vascular calcification, bone histology and cardiovascular mortality and morbidity. However, a final conclusion on the effect of cinacalcet on hard outcomes remains elusive. Etelcalcetide is a new second-generation calcimimetic with a pharmacokinetic profile that allows thrice-weekly dosing at the time of haemodialysis. It was recently approved in Europe, and is regarded as a second opportunity to improve outcomes by optimizing treatment for SHPT. In this review, we summarize the impact of cinacalcet with regard to biochemical and clinical outcomes. We also discuss the possible implications of the new calcimimetic etelcalcetide in the quest to improve outcomes.info:eu-repo/semantics/publishedVersio

Um aparato de baixo custo para medição da condutância hidráulica do xilema em plantas

Plant yield and resistance to drought are directly related to the efficiency of the xylem hydraulic conductance and the ability of this system to avoid interrupting the flow of water. In this paper we described in detail the assembling of an apparatus proposed by TYREE et al. (2002), and its calibration, as well as low cost adaptations that make the equipment accessible for everyone working in this research area. The apparatus allows measuring the conductance in parts of roots or shoots (root ramifications or branches), or in the whole system, in the case of small plants or seedlings. The apparatus can also be used to measure the reduction of conductance by embolism of the xylem vessels. Data on the hydraulic conductance of eucalyptus seedlings obtained here and other reports in the literature confirm the applicability of the apparatus in physiological studies on the relationship between productivity and water stress.A produtividade das plantas e a capacidade de resistência à seca estão diretamente relacionadas com a eficiência da condutância hidráulica do xilema e a capacidade desse sistema em evitar a interrupção do fluxo de água. No presente trabalho, detalha-se a montagem de um aparato proposto por TYREE et al. (2002), e sua calibração, bem como adaptações com peças de menor custo que tornam o aparelho acessível a qualquer um trabalhando nesta linha de pesquisa. Esse aparato possibilita medir a condutância de partes do sistema radicular ou da parte aérea (ramificações radiculares ou ramos), ou em todo o sistema, no caso de plantas de porte pequeno ou plântulas. O aparato também pode ser usado para medir a redução da condutância pela embolização dos vasos do xilema. Medições de condutância hidráulica feitas em plântulas de eucalipto e outros trabalhos encontrados na literatura confirmaram a aplicabilidade desse aparato em estudos fisiológicos de produtividade relacionada ao estresse hídrico.583587Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

INSTITUTIONALIZATION OF INFORMATION TECHNOLOGY GOVERNANCE AND THE BEHAVIOR OF INDIVIDUALS IN THE PUBLIC ORGANIZATIONS CONTEXT

IT Governance (ITG) institutionalization might reduce the negative impact of political issues on IT results especially through the behavioral pillar. This research used the Organizational Citizenship Behavior (OCB) concept to understand this phenomenon. OCB describes a person\u27s voluntary commitment to an organization that is not part of his/her contractual tasks. The goal of this study is confirming that ITG institutionalization effects civil servants’ behavior. The set of hypotheses of the theoretical-empirical model are based on the presumption that ITG institutionalization exerts a positive effect on each variable of OCB. A descriptive-confirmative ex-post facto research was operationalized through a survey research with 173 civil servants in the Executive and Judiciary Branch of a Brazilian state. A questionnaire was developed and validated through Factor Exploratory Analysis. Partial least squares structural equation modeling was used for data analysis. All hypotheses were confirmed, showing the effect of ITG institutionalization on the behavior of individuals. The theoretical contribution is the development of an ITG institutionalization construct and the demonstration of a positive and significant relationship between this and the OCB construct. The practical contribution highlights the possibility of IT managers performing their IT tasks through behavior change of individuals encouraged by the ITG institutionalization

Climate and Security: Evolution in the United States Political Discourses

Climate change emerged as a high-level global issue in the Rio Earth Summit (1992). In the United States, the Clinton Administration was the first to associate climate and security in official documents. Since then, there has been an overall tendency to consolidate climate security in political discourses in the United States. Based on the Copenhagen School criteria, analysis of speeches by Post-Cold War U.S. governments (Bill Clinton, George W. Bush, Barack Obama, Donald Trump, and Joe Biden), and a review of each Administration’s climate change policies demonstrate how climate securitization has evolved in the United States. Climate securitization has evolved as a nonlinear process characterized by periods of progress and reversals of narratives and securitizing measures with a strong influence of partisanship