IEEE Transactions on Geoscience and Remote Sensing, 2006
The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of... more The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of gross primary production (GPP) since March 2000. We compare four years (2000 to 2003) of satellite-based calculations of GPP with tower eddy CO 2 flux-based estimates across diverse land cover types and climate regimes. We examine the potential error contributions from meteorology, leaf area index (LAI)/fPAR, and land cover. The error between annual GPP computed from NASA's Data Assimilation Office's (DAO) and tower-based meteorology is 28%, indicating that NASA's DAO global meteorology plays an important role in the accuracy of the GPP algorithm. Approximately 62% of MOD15-based estimates of LAI were within the estimates based on field optical measurements, although remaining values
CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso... more CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia Solar. Helder Gonçalves, Manuel Romero (Ed.). Lisboa, Portugal: LNEG, 3-5 Novembro, 2020, p. 405-412. ISBN: 978-989-675-076-3
Glycosphingolipids in filamentous fungi are significant components of the plasma membrane and are... more Glycosphingolipids in filamentous fungi are significant components of the plasma membrane and are vital for different cellular processes, such as growth, morphological transition or signal transduction. Fungal growth inhibitors targeting glycosylinositolphosphoceramide (GIPCs) biosynthesis or antifungal compounds binding to GIPCs present in membranes could present a safe way of preventing fungal growth on crops since GIPCs are not present in mammalian cells. Mass spectrometry-based shotgun lipidomics was used to analyze sphingolipids of 11 fungal strains isolated from plant material. Molecular species with inositol ceramides containing zero to five carbohydrates were identified. Differences in the amount of individual molecular species were influenced by the taxonomic affiliation. All tested strains exhibited a relatively high content (more than 40 mol.%) of GIPCs with three and more saccharides attached to the polar head. It could be assumed that the sphingolipid profiles of the tested plant pathogens would be an adaptation mechanism to antifungal plant defensins.
Revista Interdisciplinar de Pesquisa em Engenharia, Aug 25, 2017
Due to the rapid advance in technology, a new generation of power plants has emerged: the concent... more Due to the rapid advance in technology, a new generation of power plants has emerged: the concentrated solar power (CSP). It is a renewable energy system that can be combined with large-scale energy storage systems. CSP holds many promises for the countries with high direct solar radiation, as Brazil. However, there are many problems regarding the viability of these plants in the emerging countries such as high capital costs, lack of national technology and qualified professionals. Hybridization of existing power plants with solar energy could be a possible gateway for the technology deployment. This paper presents the technical and economic feasibility analysis of a steam super-heater plant powered by CSP for electricity production. Such hybridization permits the reduction of CO 2 emissions and retrenchment in the long term. In this context, the performances of four different systems of thermoelectric power generation were compared: (i) solar reheatingsuperheated steam generated by boiler and it expansion in the first turbine using CSP for reheating second expansion turbine; (ii) solar superheater-generating saturated steam in a boiler and superheating it using CSP; (iii) supercritical solar heater-saturated steam production in a boiler and heating at supercritical steam in CSP and (iv) conventional cycle and CSP working in parallel. The direct irradiation data available at the Brazilian solar atlas were analyzed, looking for the best location of power plant installation. In addition to the solar resource data, other criteria as economic, environmental and availability of transmission lines were taken into account. The decision matrix with performance indicators helped in the decision-making process of location selection. Comparing to others scenarios the obtained results showed several advantages of scenario (iv)-conventional cycle and CSP working in parallel using solar power towers without thermal storage. Research result as well revealed Santa Maria da Vitória town, Bahia region, as a better place for plant construction using the selected scenario. The total capacity was determined to be 30 MWe in accordance with the incentives offered by 481/2012-ANEEL (Brazilian Agency) resolution.
Proceedings of the 23rd ABCM International Congress of Mechanical Engineering, 2015
Objective: To consider the use of systematic methods for categorising foods according to their nu... more Objective: To consider the use of systematic methods for categorising foods according to their nutritional quality ('nutrient profiling') as a strategy for promoting public health through better dietary choices. Methods: We describe and discuss several well-developed approaches for categorising foods using nutrient profiling, primarily in the area of food labelling and also with respect to advertising controls. The best approach should be able to summarise and synthesise key nutritional dimensions (such as sugar, fat and salt content, energy density and portion size) in a manner that is easily applied across a variety of products, is understandable to users and can be strictly defined for regulatory purposes. Results: Schemes that provide relative comparisons within food categories may have limited use, especially for foods that are not easily categorised. Most nutrient-profiling schemes do not clearly identify less-healthy foods, but are used to attract consumers towards products with supposedly better profiles. The scheme used in the UK to underpin the colour-coded 'traffic light' signalling on food labels, and the one used by the UK broadcasting regulator Ofcom to limit advertising to children, together represent the most developed use of nutrient profiling in government policy-making, and may have wider utility. Conclusion: Nutrient profiling as a method for categorising foods according to nutritional quality is both feasible and practical and can support a number of public health-related initiatives. The development of nutrient profiling is a desirable step in support of strategies to tackle obesity and other non-communicable diseases. A uniform approach to nutrient profiling will help consumers, manufacturers and retailers in Europe.
A number of recent studies have attributed a large proportion of soil respiration (Rsoil) to rece... more A number of recent studies have attributed a large proportion of soil respiration (Rsoil) to recently photoassimilated carbon (C). Time lags (tPR) associated with these pulses of photosynthesis and responses of Rsoil have been found on time scales of hours to weeks for different ecosystems, but most studies find evidence for tPR on the order of 1-5 d. We showed that such time scales are commensurate with CO2 diffusion time scales from the roots to the soil surface, and may thus be independent from photosynthetic pulses. To further quantify the role of physical (i.e. edaphic) and biological (i.e. vegetative) controls on such lags, we investigated tPR at adjacent planted pine (PP) and hardwood (HW) forest ecosystems over six and four measurement years, respectively, using both autocorrelation analysis on automated soil surface flux measurements and their lagged cross-correlations with drivers for and surrogates of photosynthesis. Evidence for tPR on the order of 1-3 d was identified in both ecosystems and using both analyses, but this lag could not be attributed to recently photoassimilated C because the same analysis yielded comparable lags at HW during leaf-off periods. Future efforts to model ecosystem C inputs and outputs in a pulse-response framework must combine measurements of transport in the physical and biological components of terrestrial ecosystems.
IEEE Transactions on Geoscience and Remote Sensing, 2006
The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of... more The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of gross primary production (GPP) since March 2000. We compare four years (2000 to 2003) of satellite-based calculations of GPP with tower eddy CO 2 flux-based estimates across diverse land cover types and climate regimes. We examine the potential error contributions from meteorology, leaf area index (LAI)/fPAR, and land cover. The error between annual GPP computed from NASA's Data Assimilation Office's (DAO) and tower-based meteorology is 28%, indicating that NASA's DAO global meteorology plays an important role in the accuracy of the GPP algorithm. Approximately 62% of MOD15-based estimates of LAI were within the estimates based on field optical measurements, although remaining values
CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso... more CIES2020: As Energias Renováveis na Transição Energética: Livro de Comunicações do XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia Solar. Helder Gonçalves, Manuel Romero (Ed.). Lisboa, Portugal: LNEG, 3-5 Novembro, 2020, p. 405-412. ISBN: 978-989-675-076-3
Glycosphingolipids in filamentous fungi are significant components of the plasma membrane and are... more Glycosphingolipids in filamentous fungi are significant components of the plasma membrane and are vital for different cellular processes, such as growth, morphological transition or signal transduction. Fungal growth inhibitors targeting glycosylinositolphosphoceramide (GIPCs) biosynthesis or antifungal compounds binding to GIPCs present in membranes could present a safe way of preventing fungal growth on crops since GIPCs are not present in mammalian cells. Mass spectrometry-based shotgun lipidomics was used to analyze sphingolipids of 11 fungal strains isolated from plant material. Molecular species with inositol ceramides containing zero to five carbohydrates were identified. Differences in the amount of individual molecular species were influenced by the taxonomic affiliation. All tested strains exhibited a relatively high content (more than 40 mol.%) of GIPCs with three and more saccharides attached to the polar head. It could be assumed that the sphingolipid profiles of the tested plant pathogens would be an adaptation mechanism to antifungal plant defensins.
Revista Interdisciplinar de Pesquisa em Engenharia, Aug 25, 2017
Due to the rapid advance in technology, a new generation of power plants has emerged: the concent... more Due to the rapid advance in technology, a new generation of power plants has emerged: the concentrated solar power (CSP). It is a renewable energy system that can be combined with large-scale energy storage systems. CSP holds many promises for the countries with high direct solar radiation, as Brazil. However, there are many problems regarding the viability of these plants in the emerging countries such as high capital costs, lack of national technology and qualified professionals. Hybridization of existing power plants with solar energy could be a possible gateway for the technology deployment. This paper presents the technical and economic feasibility analysis of a steam super-heater plant powered by CSP for electricity production. Such hybridization permits the reduction of CO 2 emissions and retrenchment in the long term. In this context, the performances of four different systems of thermoelectric power generation were compared: (i) solar reheatingsuperheated steam generated by boiler and it expansion in the first turbine using CSP for reheating second expansion turbine; (ii) solar superheater-generating saturated steam in a boiler and superheating it using CSP; (iii) supercritical solar heater-saturated steam production in a boiler and heating at supercritical steam in CSP and (iv) conventional cycle and CSP working in parallel. The direct irradiation data available at the Brazilian solar atlas were analyzed, looking for the best location of power plant installation. In addition to the solar resource data, other criteria as economic, environmental and availability of transmission lines were taken into account. The decision matrix with performance indicators helped in the decision-making process of location selection. Comparing to others scenarios the obtained results showed several advantages of scenario (iv)-conventional cycle and CSP working in parallel using solar power towers without thermal storage. Research result as well revealed Santa Maria da Vitória town, Bahia region, as a better place for plant construction using the selected scenario. The total capacity was determined to be 30 MWe in accordance with the incentives offered by 481/2012-ANEEL (Brazilian Agency) resolution.
Proceedings of the 23rd ABCM International Congress of Mechanical Engineering, 2015
Objective: To consider the use of systematic methods for categorising foods according to their nu... more Objective: To consider the use of systematic methods for categorising foods according to their nutritional quality ('nutrient profiling') as a strategy for promoting public health through better dietary choices. Methods: We describe and discuss several well-developed approaches for categorising foods using nutrient profiling, primarily in the area of food labelling and also with respect to advertising controls. The best approach should be able to summarise and synthesise key nutritional dimensions (such as sugar, fat and salt content, energy density and portion size) in a manner that is easily applied across a variety of products, is understandable to users and can be strictly defined for regulatory purposes. Results: Schemes that provide relative comparisons within food categories may have limited use, especially for foods that are not easily categorised. Most nutrient-profiling schemes do not clearly identify less-healthy foods, but are used to attract consumers towards products with supposedly better profiles. The scheme used in the UK to underpin the colour-coded 'traffic light' signalling on food labels, and the one used by the UK broadcasting regulator Ofcom to limit advertising to children, together represent the most developed use of nutrient profiling in government policy-making, and may have wider utility. Conclusion: Nutrient profiling as a method for categorising foods according to nutritional quality is both feasible and practical and can support a number of public health-related initiatives. The development of nutrient profiling is a desirable step in support of strategies to tackle obesity and other non-communicable diseases. A uniform approach to nutrient profiling will help consumers, manufacturers and retailers in Europe.
A number of recent studies have attributed a large proportion of soil respiration (Rsoil) to rece... more A number of recent studies have attributed a large proportion of soil respiration (Rsoil) to recently photoassimilated carbon (C). Time lags (tPR) associated with these pulses of photosynthesis and responses of Rsoil have been found on time scales of hours to weeks for different ecosystems, but most studies find evidence for tPR on the order of 1-5 d. We showed that such time scales are commensurate with CO2 diffusion time scales from the roots to the soil surface, and may thus be independent from photosynthetic pulses. To further quantify the role of physical (i.e. edaphic) and biological (i.e. vegetative) controls on such lags, we investigated tPR at adjacent planted pine (PP) and hardwood (HW) forest ecosystems over six and four measurement years, respectively, using both autocorrelation analysis on automated soil surface flux measurements and their lagged cross-correlations with drivers for and surrogates of photosynthesis. Evidence for tPR on the order of 1-3 d was identified in both ecosystems and using both analyses, but this lag could not be attributed to recently photoassimilated C because the same analysis yielded comparable lags at HW during leaf-off periods. Future efforts to model ecosystem C inputs and outputs in a pulse-response framework must combine measurements of transport in the physical and biological components of terrestrial ecosystems.
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Papers by Mario Siqueira