CO2-response function of radiation use efficiency in rice for climate change scenarios

The objective of this work was to evaluate a generalized response function to the atmospheric CO2 concentration [f(CO2)] by the radiation use efficiency (RUE) in rice. Experimental data on RUE at different CO2 concentrations were collected from rice trials performed in several locations around the world. RUE data were then normalized, so that all RUE at current CO2 concentration were equal to 1. The response function was obtained by fitting normalized RUE versus CO2 concentration to a Morgan-Mercer-Flodin (MMF) function, and by using Marquardt's method to estimate the model coefficients. Goodness of fit was measured by the standard deviation of the estimated coefficients, the coefficient of determination (R²), and the root mean square error (RMSE). The f(CO2) describes a nonlinear sigmoidal response of RUE in rice, in function of the atmospheric CO2 concentration, which has an ecophysiological background, and, therefore, renders a robust function that can be easily coupled to rice simulation models, besides covering the range of CO2 emissions for the next generation of climate scenarios for the 21st century.

Potencial uso de serpentinito no armazenamento mineral do CO2

Rising anthropogenic CO2 emissions are considered a major contributor to the greenhouse effect. There are several options for reducing atmospheric CO2 levels, and among these alternatives, Carbon Capture and Storage (CCS) has been identified as an effective and promising approach. This work investigated the feasibility of using serpentinite as a vehicle for carbon storage presenting a source-sink match. The main results of the work confirmed that serpentinite is appropriate for the carbonation process due to the high concentration of Mg in its composition.

Juvenile tree growth correlates with photosynthesis and leaf phosphorus content in central Amazonia

Light and soil water availability may limit carbon uptake of trees in tropical rainforests. The objective of this work was to determine how photosynthetic traits of juvenile trees respond to variations in rainfall seasonality, leaf nutrient content, and opening of the forest canopy. The correlation between leaf nutrient content and annual growth rate of saplings was also assessed. In a terra firme rainforest of the central Amazon, leaf nutrient content and gas exchange parameters were measured in five sapling tree species in the dry and rainy season of 2008. Sapling growth was measured in 2008 and 2009. Rainfall seasonality led to variations in soil water content, but it did not affect leaf gas exchange parameters. Subtle changes in the canopy opening affected CO2 saturated photosynthesis (A pot, p = 0.04). Although A pot was affected by leaf nutrient content (as follows: P > Mg > Ca > N > K), the relative growth rate of saplings correlated solely with leaf P content (r = 0.52, p = 0.003). At present, reduction in soil water content during the dry season does not seem to be strong enough to cause any effect on photosynthesis of saplings in central Amazonia. This study shows that leaf P content is positively correlated with sapling growth in the central Amazon. Therefore, the positive effect of atmospheric CO2 fertilization on long-term tree growth will depend on the ability of trees to absorb additional amount of P

Transformations in occluded light fraction organic matter in a clayey oxisol: evidence from 13C-CPMAS-NMR and delta13C Signature

We hypothesised that, during occlusion inside granular aggregates of oxide-rich soils, the light fraction organic matter would undergo a strong process of decomposition, either due to the slow process of aggregate formation and stabilisation or due to digestion in the macro- and meso-fauna guts. This process would favour the accumulation of recalcitrant materials inside aggregates. The aim of this study was to compare the dynamics and the chemical composition of free and occluded light fraction organic matter in a natural cerrado vegetation (woodland savannah) and a nearby pasture (Brachiaria spp.) to elucidate the transformations during occlusion of light fraction in aggregates of a clayey Oxisol. Nuclear Magnetic Resonance of the 13C, with Cross Polarisation and Magic Angle Spinning (13C-CPMAS-NMR), and 13C/12C isotopic ratio were combined to study organic matter composition and changes in carbon dynamics, respectively. The occluded light fraction had a slower turnover than the free light fraction and the heavy fraction. Organic matter in the occluded fraction also showed a higher degree of decomposition. The results confirm that processes of soil organic matter occlusion in the typical "very fine strong granular" structure of the studied oxide-rich soil led to an intense transformation, selectively preserving stable organic matter. The small amount of organic material stored as occluded light faction, as well as its stability, suggests that this is not an important or manageable sink for sequestration of atmospheric CO2.

Environmental and agricultural benefits of a management system designed for sandy loam soils of the humid tropics

A sustainable management of soils with low natural fertility on family farms in the humid tropics is a great challenge and overcoming it would be an enormous benefit for the environment and the farmers. The objective of this study was to assess the environmental and agronomic benefits of alley cropping, based on the evaluation of C sequestration, soil quality indicators, and corn yields. Combinations of four legumes were used in alley cropping systems in the following treatments: Clitoria fairchildiana + Cajanus cajan; Acacia mangium + Cajanus cajan; Leucaena leucocephala + Cajanus cajan; Clitoria fairchildiana + Leucaena leucocephala; Leucaena leucocephala + Acacia mangium and a control. Corn was used as a cash crop. The C content was determined in the different compartments of soil organic matter, CEC, available P, base saturation, percentage of water saturation, the period of the root hospitality factor below the critical level and corn yield. It was concluded that alley cropping could substitute the slash and burn system in the humid tropics. The main environmental benefit of alley cropping is the maintenance of a dynamic equilibrium between C input and output that could sustain up to 10 Mg ha-1 of C in the litter layer, decreasing atmospheric CO2 levels. Alley cropping is also beneficial from the agricultural point of view, because it increases base saturation and decreases physical resistance to root penetration in the soil layer 0 - 10 cm, which ensures the increase and sustainability of corn yield.

Plant growth and leaf-spot severity on eucalypt at different CO2concentrations in the air

The objective of this work was to evaluate the effects of increased air-CO2 concentration on plant growth and on leaf-spot caused by Cylindrocladium candelabrumin Eucalyptus urophylla. Seedlings were cultivated for 30 days at 451, 645, 904, and 1,147 µmol mol-1 CO2 ; then, they were inoculated with the pathogen and kept under the same conditions for seven days. Increased CO2concentration increased plant height and shoot dry matter mass, and decreased disease incidence and severity. Stem diameter was not affected by the treatments. Increased concentrations of atmospheric CO2 favorably affect eucalypt growth and reduce leaf-spot severity.

Climate change and future scenarios for palisade grass production in the state of São Paulo, Brazil

The objective of this work was to analyze future scenarios for palisade grass yield subjected to climate change for the state of São Paulo, Brazil. An empirical crop model was used to estimate yields, according to growing degree-days adjusted by one drought attenuation factor. Climate data from 1963 to 2009 of 23 meteorological stations were used for current climate conditions. Downscaled outputs of two general circulation models were used to project future climate for the 2013-2040 and 2043-2070 periods, considering two contrasting scenarios of temperature and atmospheric CO2 concentration increase (high and low). Annual dry matter yield should be from 14 to 42% higher than the current one, depending on the evaluated scenario. Yield variation between seasons (seasonality) and years is expected to increase. The increase of dry matter accumulation will be higher in the rainy season than in the dry season, and this result is more evident for soils with low-water storage capacity. The results varied significantly between regions (<10% to >60%). Despite their higher climate potential, warmer regions will probably have a lower increase in future forage production.

Bioprocessos para remoção de dióxido de carbono e óxido de nitrogênio por micro-algas visando a utilização de gases gerados durante a combustão do carvão

The aim of this work was to study the removal of CO2 and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed µmax and Xmax (0.11 d-1, 1.11 g L-1 d-1) when treated with CO2 and NaNO3. The maximum CO2 removal was 22.97% for S. obliquus treated with KNO3 and atmospheric CO2. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO2. Coupling the cultivation of these microalgae with the removal of CO2 and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions.

Growth inhibitors in turfgrass

Well-maintained lawns are comfortable and safe places for leisure activities and sports practice, and they also bring environmental benefits; for example, they reduce soil exposure to erosion and releases atmospheric CO2, thus reducing the greenhouse effect. However, regardless of the purpose of use or the choice of the plant species to form the lawn, the highest costs involve cutting that is needed to keep the turfgrass at its appropriate height. Successive lawn cutting operations are necessary basically because of the vegetative and reproductive growth of turfgrass which, in Brazil, occurs mainly from October to March. Expenditures with successive mechanical cuttings have fostered the search of alternative procedures to keep lawn plants at appropriate height, such as the use of plant growth inhibitors, an increasingly interesting procedure. Since the use of this technology in Brazil is still at its early stage, the aim of this literature review is to examine aspects associated with lawn management by using growth inhibitors. Another alternative is to increase the knowledge of the classification and rational application of the different compounds currently available in the market.

Temperature and atmospheric pressure may be considered as predictors for the occurrence of bacillary dysentery in Guangzhou, Southern China

Introduction The control of bacillary dysentery (BD) remains a big challenge for China. Methods Negative binomial multivariable regression was used to study relationships between meteorological variables and the occurrence of BD during the period of 2006-2012. Results Each 1°C rise of temperature corresponded to an increase of 3.60% (95%CI, 3.03% to 4.18%) in the monthly number of BD cases, whereas a 1 hPa rise in atmospheric pressure corresponded to a decrease in the number of BD cases by 2.85% (95%CI = 3.34% to 2.37% decrease). Conclusions Temperature and atmospheric pressure may be considered as predictors for the occurrence of BD in Guangzhou.

Caracterização química de extratos de Ocimum basilicum L. obtidos através de extração com CO2 a altas pressões

This work reports extraction yield and chemical characterization of the extracts obtained by high-pressure CO2 extraction of a cultivar of Ocimum basilicum L. The experiments were performed in the temperature range of 20 to 50 °C, from 100 to 250 atm of pressure. Chemical analyses were carried out by gas chromatography coupled to mass spectrometry, permitting to identify 23 compounds that were grouped into five chemical classes. Results showed that temperature and solvent density influenced positively the extraction yield. At 20 °C and 0.41 g cm-3 occurred a rise in the concentration of monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes.

Climatic changes: what if the global increase of CO2 emissions cannot be kept under control?

Climatic changes threaten the planet. Most articles related to the subject present estimates of the disasters expected to occur, but few have proposed ways to deal with the impending menaces. One such threat is the global warming caused by the continuous increase in CO2 emissions leading to rising ocean levels due to the increasing temperatures of the polar regions. This threat is assumed to eventually cause the death of hundreds of millions of people. We propose to desalinize ocean water as a means to reduce the rise of ocean levels and to use this water for populations that need good quality potable water, precisely in the poorest regions of the planet. Technology is available in many countries to provide desalinated water at a justifiable cost considering the lives threatened both in coastal and desertified areas.

Avaliação da voz em pacientes submetidos à cordectomia com laser de CO2

OBJETIVO: Avaliar a voz de pacientes portadores de carcinomas iniciais glóticos submetidos à cordectomia com laser de CO2. MÉTODO: Foram avaliados 15 pacientes com diagnóstico de carcinoma espinocelular Tis e T1 glóticos. A avaliação foi feita por meio da análise perceptivo auditiva da voz, pela análise acústica computadorizada e videolaringoestroboscópica. Os pacientes responderam a um questionário de avaliação geral da voz e um protocolo de qualidade de vida relacionado à voz (QVV). Os resultados foram comparados aos de um grupo controle de indivíduos com laringes normais. RESULTADOS: A análise perceptivo-auditiva da voz revelou que a maioria dos pacientes submetidos à cordectomia apresentou algum grau de disfonia, à custa de rouquidão e soprosidade. Considerando os parâmetros acústicos analisados e os valores do grupo controle, observou-se a tendência de um pequeno incremento da freqüência fundamental, mas sem diferença estatisticamente significante; os valores de jitter, shimmer e da proporção harmônico-ruído apresentaram-se significantemente alterados. Os aspectos analisados na videolaringoestroboscopia mostraram-se melhores nas cordectomias menos extensas. Os escores do QVV sugerem que os pacientes tiveram um discreto impacto na qualidade de vida relacionada à voz. CONCLUSÕES: Apesar da presença de alterações na qualidade vocal dos pacientes submetidos à cordectomia com laser de CO2, os resultados funcionais tendem a ser bem aceitos pelos pacientes, com discreta repercussão na qualidade de vida.

Brazil's rise on the international scene: Brazil and the World

Since Cardoso and during Lula's Administration, the international order has undergone significant changes. These changes have allowed the Brazilian foreign policy to mitigate internal effects of an order established by others and, at the same time, to become an active participant in the formulation of the new order. To democratize globalization became the mainspring of Brazilian foreign policy. In the scope, President Lula has maintained the tradition of formulating and programming foreign policy as a State policy, and also has fostered the logistic strategy of incorporation of Brazil into the international scene.

Japan and India: soft balancing as a reaction to China's rise?

What are Indian and Japanese reactions to China's rise in economic, political and military terms? According to realist tradition, their option would be between balancing and bandwagoning. Applying Stephen Walt's balance of threats approach, this work aims to analyze Indian and Japan responses to an increasingly powerful China; its conclusions point to an evolving relationship between India and Japan, in military terms, especially after 2005.