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Åtgärder för ökad markanvändning i solcellspark : En tekno-ekonomisk fallstudie om potentialen hos bifacial och solföljare i Solpark FyrislundMajid, Safwat January 2021 (has links)
Solar parks are increasingly getting a larger market share of PV installations over the world, and have for the last couple of years managed to establish itself in the Swedish market. The market has for a long time been known for its decline in module prices, which has allowed an emergence of more efficient PV-techniques such as one-axis trackers and bifacial modules. Bifacial modules use the backside of modules for improved utiliziation of incoming light, while one-axis trackers have the ability to track the sun in order to maximise light absorption. These innovations have now caught the interest of companies willing to invest in large-scale PV-farms, where efficient land use is highly regarded. The aim of this thesis was to examine how bifacial modules and one-axis trackers perform in terms of system performance and profitabilty if implemented in 'Solpark Fyrislund', a solar park owned by Vasakronan AB. This was done by modelling and simulating cases in which said techniques were incorporated. The data was later used to estimate profitabilty of each investigated case. Results showed that the highest system performance and profitability was achieved by installing bifacial modules on the site. One-axis trackers are currently too expensive, require higher maintenance and has a higher demand for land, resulting in its profitability not being justified. It was also found that the current configuration could be optimized further for higher profit, by slightly reducing the pitch as well as increasing the tilt of the existing modules. The study should be followed up by further investigating the use of backtracking for one-axis trackers. Said innovations should also be more established in the Swedish market so that CAPEX- and OPEX prices become more accessible.
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Modeling of an Electrolysis System for Techno-Economic Optimization of Hydrogen ProductionKöstlbacher, Jürgen January 2023 (has links)
In face of climate change, Europe and other global actors are in the process of transitioning to carbon-neutral economies, aiming to phase out of fossil fuels and power industries with renewable energies. Hydrogen is going to play a crucial role in the transition, replacing fossil fuels in hard-to-decarbonize industries and acting as energy carrier and energy storage for renewable electricity. However, the hydrogen production method with the lowest carbon intensity, water electrolysis in combination with renewable electricity, is often not cost competitive to other production methods. Even though policies and initiatives are providing subsidies to scale up low-carbon hydrogen production, companies hesitate to invest due to the complexity of hydrogen production systems and the uncertainties of cost competitiveness. This research aims to develop a tool for optimizing the capacity of a water electrolysis system to produce low-carbon hydrogen and to lay the groundwork for optimizing the operation of electrolysis hydrogen production plants. The objective is to find the optimal plant capacity to achieve the lowest cost of hydrogen production for a defined hydrogen demand and energy supply. The scope is limited to the electrolysis system as optimizing asset which is modeled with technology-specific costs and characteristics, gained from manufacturer interviews and internal company data. This includes the often neglected characteristics of load-dependent efficiency and degradation effects. Further, the tool is enabled to buy and sell electricity on the spot market according to predicted prices in order to minimize the electricity costs. The developed tool is tested, benchmarked and applied to two different industry-based test scenarios in Germany and Portugal. The test scenario in Germany describes a mid-scale hydrogen production case for a transport application with a demand increase over 10 years (80 to 1,800 tons per year) and regional renewable energy supply via power purchase agreements. The lowest costs of hydrogen production for this scenario can be reached with an alkaline electrolysis system of a capacity of 16 MWel considering only renewable energy sources, achieving a LCOH of 4.75 €/kg of green hydrogen. The second test scenario describes a large-scale production case in Portugal for application in the refinery industry. The yearly hydrogen demand increases from 5,000 tons up to 17,100 tons within three years and is assumed to stay constant for the residual years. The electricity for the electrolysis process is secured through large solar PV and offshore wind power purchase agreements. Utilizing the alkaline electrolysis technology with a capacity of 128 MWel, a LCOH of 3.31 €/kg of green hydrogen can be achieved at the output point of the plant. The study concludes that the optimal solution and the achievable hydrogen production costs are highly dependent on the hydrogen demand (quantity and profile), the energy supply (quantity, profile, costs), and the chosen technology (efficiency, degradation, costs) and need to be evaluated under the case-specific prerequisites. The thesis further highlights the significant impact of the electrolysis system efficiency and capital expenditures on the capacity decision and achievable hydrogen production costs. / Mot bakgrund av klimatförändringarna håller Europa och andra globala aktörer på att ställa om till koldioxidneutrala ekonomier, med målet att fasa ut fossila bränslen och driva industrier med förnybara energikällor. Vätgas kommer att spela en avgörande roll i omställningen genom att ersätta fossila bränslen i industrier som är svåra att koldioxidneutralisera och fungera som energibärare och energilagring för förnybar el. Den metod för vätgasproduktion som har lägst koldioxidintensitet, vattenelektrolys i kombination med förnybar el, är dock ofta inte kostnadsmässigt konkurrenskraftig i förhållande till andra produktionsmetoder. Även om politik och initiativ tillhandahåller subventioner för att skala upp koldioxidsnål vätgasproduktion, tvekar företagen på grund av komplexiteten i vätgasproduktionssystemen och osäkerheten kring konkurrenskraften. Denna forskning syftar till att utveckla ett verktyg för att optimera kapaciteten hos ett vattenelektrolyssystem för att producera grön vätgas och att lägga grunden för att optimera driften av elektrolysanläggningar för vätgasproduktion. Målet är att hitta den optimala anläggningskapaciteten för att uppnå den lägsta kostnaden för vätgasproduktion för en definierad vätgasefterfrågan och definierad energiförsörjning. Omfattningen är begränsad till elektrolyssystemet som en optimerande tillgång som modelleras med teknikspecifika kostnader och egenskaper, hämtade från tillverkar-intervjuer och från företags interna marknadsdata. Detta inkluderar de ofta försummade egenskaperna hos lastberoende effektivitet och degraderingseffekter. Vidare kan verktyget köpa och sälja el på spotmarknaden enligt förutspådda priser för att minimera elkostnaderna. Det utvecklade verktyget testas, jämförs och tillämpas på två olika industribaserade testscenarier i Tyskland och Portugal. Testscenariot i Tyskland beskriver en medelstor vätgasproduktion för en transporttillämpning där efterfrågan ökar över 10 år (80 till 1 800 ton per år) och regional förnybar energiförsörjning via energiköpsavtal (power purchase agreements). De lägsta kostnaderna för vätgasproduktion för detta scenario kan uppnås med ett alkaliskt elektrolyssystem med en kapacitet på 16 MWel som endast använder förnyelsebara energikällor och uppnår en LCOH på 4,75 €/kg grön vätgas. Det andra testscenariot beskriver en storskalig vätgasproduktion i Portugal för tillämpning inom raffinaderi-industrin. Det årliga vätgasbehovet ökas från 5 000 ton till 17 100 ton inom tre år och antogs förbli konstant under de återstående åren. El för elektrolysprocessen säkras genom stora energiköpsavtal (power purchase agreements) för solceller och havsbaserad vindkraft. Genom att använda alkalisk elektrolysteknik med en kapacitet på 128 MWel kan en LCOH på 3,31 €/kg grön vätgas uppnås vid anläggningens utgångspunkt. Studien visar att den optimala lösningen och de uppnåbara vätgasproduktionskostnaderna är starkt beroende av vätgasbehovet (mängd och profil), energiförsörjningen (mängd, profil, kostnader) och den valda tekniken (effektivitet, nedbrytning, kostnader) och måste utvärderas utifrån de fallspecifika förutsättningarna. Avhandlingen belyser vidare den betydande inverkan som elektrolyssystemets effektivitet och kapitalutgifter har på kapacitetsbeslutet och de uppnåeliga kostnaderna för vätgasproduktion.
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Características da ocupação na área de preservação permanente : APP do Arroio Pitangueiras no município de Santo Antônio da Patrulha - RSFraga, Josélia Maria Lorence January 2009 (has links)
Este trabalho refere-se à identificação das diferentes categorias de ocupação urbana que transgridem a legislação ambiental sobre as Áreas de Preservação Permanente – APPs. Para compreender os fatores de conflitos e de impactos nesses espaços, foi selecionada, como recorte territorial para realização da pesquisa, a faixa marginal ao arroio Pitangueiras que atravessa a área urbana do município de Santo Antônio da Patrulha - RS e onde a ocupação da APP é uma situação notável e problemática. A crescente ocupação desses espaços tem expressado, nas cidades, graves situações de conflito: de um lado, os impactos ambientais resultantes da ocupação dessas áreas; por outro, a necessidade em considerar o contexto e a forma de ocupação social das APPs ao longo do tempo. Atualmente, existem 143 casas estabelecidas na faixa marginal de 30 metros de APP do arroio Pitangueiras, estando as mesmas em desconformidade com o Código Florestal Brasileiro. Os resultados mostraram que a população residente nessa área apresenta deficiências de atendimento no ponto de vista de saneamento básico, saúde, educação, e nos aspectos sociais, a exemplo de trabalho e geração de renda. Os fatores de impacto ambiental levantados mostraram uma relação direta com os dados de densidade populacional. A metodologia Monalisa permitiu classificar a bacia hidrográfica do arroio Pitangueiras como fortemente impactada em razão da sobreposição dos impactos identificados em campo. A classificação das Áreas de Influência Direta (AID) em APPs possibilitou a compreensão da situação real e a proposição de estratégias de ação e metas para a gestão ambiental das áreas de preservação permanente inseridas no meio ambiente urbano. / The present paper refers to the identification of different categories of urban occupancy which transgress the environmental legislation about Permanent Preservation Areas (PPAs). In order to figure out the conflict and impact factors in these spaces the marginal strip of Arroio Pitangueiras which crosses the urban area of Santo Antonio da Patrulha territory was chosen as a territorial clipping to accomplish the research. It is where the PPA occupancy is a detachable and problematic situation. The growing occupancy of these lands has expressed serious conflict situations in the cities: on the one hand, the environmental impacts resulting from the occupancy of these areas; on the other hand, the need to consider the context and the manner of social occupancy of the PPAs along the time. Nowadays there are 143 houses settled in 30 meters marginal strip of Arroio Pitangueiras and they are not according to the Brazilian Forest Code. The results showed that the population that lives in this area presents lacking of assistance from basic sanitation, health, instruction, and from social aspects, work and revenue generation. The environmental impact factors raised showed a straight relationship with population density data. Monalisa methodology allowed to rate the Arroio Pitangueiras river basin as strongly impacted due to the sobreposition of impacts identified in the field. The Direct Influence Areas (DIA) rate in PPAs helped to understand the real situation as well as the proposition of strategies of action and goals to the environmental administration of the permanent preservation areas inserted in the urban environment.
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Características da ocupação na área de preservação permanente : APP do Arroio Pitangueiras no município de Santo Antônio da Patrulha - RSFraga, Josélia Maria Lorence January 2009 (has links)
Este trabalho refere-se à identificação das diferentes categorias de ocupação urbana que transgridem a legislação ambiental sobre as Áreas de Preservação Permanente – APPs. Para compreender os fatores de conflitos e de impactos nesses espaços, foi selecionada, como recorte territorial para realização da pesquisa, a faixa marginal ao arroio Pitangueiras que atravessa a área urbana do município de Santo Antônio da Patrulha - RS e onde a ocupação da APP é uma situação notável e problemática. A crescente ocupação desses espaços tem expressado, nas cidades, graves situações de conflito: de um lado, os impactos ambientais resultantes da ocupação dessas áreas; por outro, a necessidade em considerar o contexto e a forma de ocupação social das APPs ao longo do tempo. Atualmente, existem 143 casas estabelecidas na faixa marginal de 30 metros de APP do arroio Pitangueiras, estando as mesmas em desconformidade com o Código Florestal Brasileiro. Os resultados mostraram que a população residente nessa área apresenta deficiências de atendimento no ponto de vista de saneamento básico, saúde, educação, e nos aspectos sociais, a exemplo de trabalho e geração de renda. Os fatores de impacto ambiental levantados mostraram uma relação direta com os dados de densidade populacional. A metodologia Monalisa permitiu classificar a bacia hidrográfica do arroio Pitangueiras como fortemente impactada em razão da sobreposição dos impactos identificados em campo. A classificação das Áreas de Influência Direta (AID) em APPs possibilitou a compreensão da situação real e a proposição de estratégias de ação e metas para a gestão ambiental das áreas de preservação permanente inseridas no meio ambiente urbano. / The present paper refers to the identification of different categories of urban occupancy which transgress the environmental legislation about Permanent Preservation Areas (PPAs). In order to figure out the conflict and impact factors in these spaces the marginal strip of Arroio Pitangueiras which crosses the urban area of Santo Antonio da Patrulha territory was chosen as a territorial clipping to accomplish the research. It is where the PPA occupancy is a detachable and problematic situation. The growing occupancy of these lands has expressed serious conflict situations in the cities: on the one hand, the environmental impacts resulting from the occupancy of these areas; on the other hand, the need to consider the context and the manner of social occupancy of the PPAs along the time. Nowadays there are 143 houses settled in 30 meters marginal strip of Arroio Pitangueiras and they are not according to the Brazilian Forest Code. The results showed that the population that lives in this area presents lacking of assistance from basic sanitation, health, instruction, and from social aspects, work and revenue generation. The environmental impact factors raised showed a straight relationship with population density data. Monalisa methodology allowed to rate the Arroio Pitangueiras river basin as strongly impacted due to the sobreposition of impacts identified in the field. The Direct Influence Areas (DIA) rate in PPAs helped to understand the real situation as well as the proposition of strategies of action and goals to the environmental administration of the permanent preservation areas inserted in the urban environment.
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Características da ocupação na área de preservação permanente : APP do Arroio Pitangueiras no município de Santo Antônio da Patrulha - RSFraga, Josélia Maria Lorence January 2009 (has links)
Este trabalho refere-se à identificação das diferentes categorias de ocupação urbana que transgridem a legislação ambiental sobre as Áreas de Preservação Permanente – APPs. Para compreender os fatores de conflitos e de impactos nesses espaços, foi selecionada, como recorte territorial para realização da pesquisa, a faixa marginal ao arroio Pitangueiras que atravessa a área urbana do município de Santo Antônio da Patrulha - RS e onde a ocupação da APP é uma situação notável e problemática. A crescente ocupação desses espaços tem expressado, nas cidades, graves situações de conflito: de um lado, os impactos ambientais resultantes da ocupação dessas áreas; por outro, a necessidade em considerar o contexto e a forma de ocupação social das APPs ao longo do tempo. Atualmente, existem 143 casas estabelecidas na faixa marginal de 30 metros de APP do arroio Pitangueiras, estando as mesmas em desconformidade com o Código Florestal Brasileiro. Os resultados mostraram que a população residente nessa área apresenta deficiências de atendimento no ponto de vista de saneamento básico, saúde, educação, e nos aspectos sociais, a exemplo de trabalho e geração de renda. Os fatores de impacto ambiental levantados mostraram uma relação direta com os dados de densidade populacional. A metodologia Monalisa permitiu classificar a bacia hidrográfica do arroio Pitangueiras como fortemente impactada em razão da sobreposição dos impactos identificados em campo. A classificação das Áreas de Influência Direta (AID) em APPs possibilitou a compreensão da situação real e a proposição de estratégias de ação e metas para a gestão ambiental das áreas de preservação permanente inseridas no meio ambiente urbano. / The present paper refers to the identification of different categories of urban occupancy which transgress the environmental legislation about Permanent Preservation Areas (PPAs). In order to figure out the conflict and impact factors in these spaces the marginal strip of Arroio Pitangueiras which crosses the urban area of Santo Antonio da Patrulha territory was chosen as a territorial clipping to accomplish the research. It is where the PPA occupancy is a detachable and problematic situation. The growing occupancy of these lands has expressed serious conflict situations in the cities: on the one hand, the environmental impacts resulting from the occupancy of these areas; on the other hand, the need to consider the context and the manner of social occupancy of the PPAs along the time. Nowadays there are 143 houses settled in 30 meters marginal strip of Arroio Pitangueiras and they are not according to the Brazilian Forest Code. The results showed that the population that lives in this area presents lacking of assistance from basic sanitation, health, instruction, and from social aspects, work and revenue generation. The environmental impact factors raised showed a straight relationship with population density data. Monalisa methodology allowed to rate the Arroio Pitangueiras river basin as strongly impacted due to the sobreposition of impacts identified in the field. The Direct Influence Areas (DIA) rate in PPAs helped to understand the real situation as well as the proposition of strategies of action and goals to the environmental administration of the permanent preservation areas inserted in the urban environment.
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Daily life of persons with dementia and their spouses supported by a passive positioning alarmOlsson, Annakarin January 2013 (has links)
The overall aim was to describe how persons with dementia (PwDs) reflecton being outdoors and to investigate the support provided by a passivepositioning alarm (PPA) in making daily life safer for PwDs and theirspouses. Repeated conversations were held with 11 PwDs living in their own homesregarding their reflections on being outdoors (Study I). Interview study with14 spouses to a person with dementia (PwD) with their reflections on differentkinds of information and communication technology (ICT) devicesthat were used or can be used in the daily care of PwDs (Study II). An ethnographicapproach with participant observations and conversations withfive couples, a PwD and his/her spouse, describing and exploring their useand experiences of using a PPA, over time, in daily life (Study III). An experimentalsingle-case ABAB-design with three cases, a PwD and hisspouse, investigating the effects of using tracking technology on independentoutdoor activities and psychological well-being (Study IV). In summary, the results of the thesis show that being outdoors was describedby the PwDs as a confirmation of their identity, the `Self´. The useof ICT in daily care of PwDs was described by the spouses as shifting betweentheir own needs for safety and security and the perceived need forsafety and security from the perspective of the PwD. The use of a PPA indaily life among PwDs living in their own homes can give a sense of freedom,support and strengthen the feeling of independence for both PwDsand their spouses as well as give a feeling of safety and security for themboth. Use of the PPA may also increase PwDs’ independent outdoor activitiesand decrease spouses’ worries.
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Identifikace a ocenění zákaznických vztahů a kvalifikované pracovní síly v kontextu PPA / Identification and valuation of customer relationships and assembled workforce in the context of PPAPernica, Ondřej January 2009 (has links)
The diploma thesis deals with valuation of two types of intangible property in context on financial reporting, specifically purchase price allocation according to IAS/IFRS. The theoretical part describes the framework and specifics of valuation for financial reporting purposes and the basic valuation approaches and methods. An emphasis is placed on the multi-period excess earnings method, which is typically used for valuation of exotic intangible assets. In the practical part there is a demonstration of valuation of customer relationships in the banking sector by the multi-period excess earnings method and valuation of assembled workforce, including a discussion of potential weak points and possible variations of the commonly used income-based valuation method.
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A institucionalização do plano plurianual (PPA): um estudo no governo federal brasileiro nos períodos de 2000-2003 e 2004-2007 / The institutionalization of the plurianual plan (PPA): a study in the Brazilian federal government in the periods 2000-2003 and 2004-2007Amorim, Ivan Trizi 18 November 2016 (has links)
A promulgação da Carta Magna de 1988 resgatou a prática do planejamento governamental no Brasil ao trazer sua previsão constitucional, notadamente do plano plurianual (PPA), que se iniciou no período de 1991-1996 e encontra-se no período de 2016-2019. O PPA é um instrumento que determina, entre outros, as diretrizes, objetivos e metas da administração. Dito isso, esta pesquisa propõe o estudo da institucionalização do planejamento governamental na gestão pública contemporânea brasileira, tendo como instrumentos os PPAs do nível federal dos períodos de 2000 a 2003 e 2004 a 2007. Utilizando-se da pesquisa qualitativa, foram realizadas análises documentais, revisão da literatura e entrevistas. Os resultados apresentados demonstram as inovações trazidas e a identidade constituída pelo PPA 2000-2003, tendo sua metodologia continuada e aprofundada no PPA seguinte, relativo ao período de 2004-2007. / The sealing of Magna Carta in 1988 recovers the practice of public planning in Brazil through the Constitutional forecast, known as plurianual plan (PPA). The first plan was introduced in 1991-1996 and the currently plan is 2016-2019. PPA is a instrument of governmental planning which also establish guidelines, goals and targets. Accordingly it, the purpose of this article is to study the institutionalization of governmental plan in the contemporary Brazilian public administration, using as support the Federal PPAs 2000-2003 and 2004-2007. It was used qualitative research, specifically documental analysis, bibliographic review and interviews. The results shows the innovation and identity achieved in the PPA 2000-2003 and the methodology maintained in the following, PPA 2004-2007.
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Oscillatory Network Dynamics in Perceptual Decision-MakingChand, Ganesh 17 December 2015 (has links)
Synchronized oscillations of ensembles of neurons in the brain underlie human cognition and behaviors. Neuronal network oscillations can be described by the physics of coupled dynamical systems. This dissertation examines the dynamic network activities in two distinct neurocognitive networks, the salience network (SN) and the ventral temporal cortex-dorsolateral prefrontal cortex (VTC-DLPFC) network, during perceptual decision-making (PDM).
The key nodes of the SN include the right anterior insula (rAI), left anterior insula (lAI), and dorsal anterior cingulate cortex (dACC) in the brain. When and how a sensory signal enters and organizes within the SN before reaching the central executive network including the prefrontal cortex has been a mystery. Second, prior studies also report that perception of visual objects (face and house) involves a network of the VTC—the fusiform face area (FFA) and para-hippocampal place area (PPA)—and the DLPFC. How sensory information enters and organizes within the VTC-DLPFC network is not well understood, in milliseconds time-scale of human’s perception and decision-making. We used clear and noisy face/house image categorization tasks and scalp electroencephalography (EEG) recordings to study the dynamics of these networks. We demonstrated that beta (13–30 Hz) oscillation bound the SN, became most active around 100 ms after the stimulus onset, the rAI acted as a main outflow hub within the SN, and the SN activities were negatively correlated with the difficult tasks. We also uncovered that the VTC-DLPFC network activities were mediated by beta (13-30 Hz) and gamma (30-100 Hz) oscillations. Beta activities were enhanced in the time frame 125-250 ms after stimulus onset, the VTC acted as main outflow hub, and network activities were negatively correlated with the difficult tasks. In contrast, gamma activities were elevated in the time frame 0-125 ms, the DLPFC acted as a main outflow hub, and network activities—specifically the FFA-PPA pair—were positively correlated with the difficult tasks. These findings significantly enhance our understanding of how sensory information enters and organizes within the SN and the VTC-DLPFC network, respectively in PDM.
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Efeito do Ãcido abscÃsico nas bombas de prÃtons vacuolares e enzimas antioxidantes em Vigna unguiculata (L.) Walp / Effect of abscisic acid in vacuolar proton pumps and antioxidant enzymes in Vigna unguiculata (L.) WalpDeborah Moura RebouÃas 16 February 2011 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O Ãcido abscÃsico (ABA) à um fitohormÃnio que desempenha papÃis crÃticos na regulaÃÃo das respostas das plantas ao crescimento e desenvolvimento. O vacÃolo de plantas superiores à uma organela que ocupa a maior parte da cÃlula. A condiÃÃo de acidez à mantida por duas bombas de prÃtons distintas, V-ATPase e V-PPase. Sabe-se que estas bombas de prÃtons desempenham um papel essencial nas respostas das plantas Ãs mudanÃas ambientais. O gradiente eletroquÃmico promovido por essas enzimas à a forÃa motriz para o acÃmulo de Ãons e outros solutos no vacÃolo, sendo importante para manter a homeostase citosÃlica de Ãons e o metabolismo celular. As enzimas antioxidantes constituem um sistema de defesa contra as espÃcies reativas de oxigÃnio, que podem provocar danos ao desenvolvimento das plantas. O
objetivo deste trabalho foi estudar o efeito do Ãcido abscÃsico nos parÃmetros de crescimento e fisiolÃgicos, bem como o efeito na atividade hidrolÃtica e na expressÃo de transcritos das bombas de prÃtons vacuolares e na atividade de enzimas antioxidantes de plantas de Vigna unguiculata. As sementes de V. unguiculata foram germinadas em areia, onde cresceram por 15 dias, com aplicaÃÃo de soluÃÃo nutritiva de Hoagland na ausÃncia (controle) ou presenÃa de ABA 0,1 ÂM no terceiro, no sÃtimo e no dÃcimo dias apÃs a germinaÃÃo. Os efeitos do Ãcido abscÃsico (ABA) sobre o crescimento, a condutÃncia estomÃtica, a transpiraÃÃo, a fotossÃntese, a concentraÃÃo interna de CO2, a atividade e a expressÃo da subunidade A da V-ATPase e da V-PPase e a atividade de enzimas antioxidantes de Vigna unguiculata foram analisados. ABA aumentou o crescimento das plantas, mas nÃo afetou os parÃmetros fisiolÃgicos; induziu um aumento na atividade hidrolÃtica da V-ATPase em folhas e da V-
PPase em raÃzes; aumentou os transcritos de VuVHA-A e de VuVHP em folhas e diminuiu os transcritos de VuVHA-A em raÃzes e, por fim, causou aumento na atividade da catalase de folhas e de raÃzes. Esses resultados sugerem que o Ãcido abscÃsico regula a atividade e a expressÃo dos genes das bombas de prÃtons vacuolares, bem como as atividades de enzimas antioxidantes, sendo portanto importantes efetores que regulam o desenvolvimento de plantas de V. unguiculata. / Abscisic acid (ABA) is a phytohormone that plays critical roles in regulating plant responses
to growth and development. The vacuole of higher plants is an organelle that occupies a
larger part of the cell. The acidic condition is maintained by two distinct proton pumps, VATPase
and V-PPase. It is known these proton pumps play essential roles in plant responses
to environmental changes. The electrochemical gradient promoted by these enzymes is the
driving force for the accumulation of ions and other solutes in the vacuole, being important to
maintain cytosolic ion homeostasis and cellular metabolism. Antioxidant enzymes constitute a
defense system against reactive oxygen species, which can cause damage to plant
development. The aim of this study was to study the effect of the abscisic acid in the growth
and physiological parameters, as well as the effect on vacuolar proton pumps and antioxidant
enzymes (SOD, CAT and APX) from Vigna unguiculata cv. Pitiuba. The seeds of V.
unguiculata were germinated in sand and grown for 15 days, with application of Hoagland
solution in the absence (control) or presence of 0.1 ÂM ABA in the third, seventh and tenth
days after germination.The effects of the abscisic acid (ABA) on the growth, stomatal
conductance, transpiration, photosynthesis, internal CO2 concentration, V-ATPase subunit A
and V-PPase activities and expression and antioxidant enzymes activities of Vigna
unguiculata were analyzed. ABA increased the plants growth but did not affect the
physiological parameters; induced an increase on V-ATPase hidrolytyc activity in leaves and
on V-PPase in roots; ABA increased the transcripts of VuVHA-A and VuVHP in leaves and
decreased the VuVHA-A transcripts in roots; caused increase in the leaves and roots catalase
activity. These results suggest that the abscisic acid regulate the activity and the genes
expression of the vacuolar proton pumps, as well as the antioxidant enzymes activity, being
thus important effectors that regulate the development of V. unguiculata plants.
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