Mitigation of methane and nitrous oxide emissions from flood-irrigated rice by no incorporation of winter crop residues into the soil

Winter cover crops are sources of C and N in flooded rice production systems, but very little is known about the effect of crop residue management and quality on soil methane (CH4) and nitrous oxide (N2O) emissions. This study was conducted in pots in a greenhouse to evaluate the influence of crop residue management (incorporated into the soil or left on the soil surface) and the type of cover-crop residues (ryegrass and serradella) on CH4 and N2O emissions from a flooded Albaqualf soil cultivated with rice (Oryza sativa L.). The closed chamber technique was used for air sampling and the CH4 and N2O concentrations were analyzed by gas chromatography. Soil solution was sampled at two soil depths (2 and 20 cm), simultaneously to air sampling, and the contents of dissolved organic C (DOC), NO3-, NH4+, Mn2+, and Fe2+ were analyzed. Methane and N2O emissions from the soil where crop residues had been left on the surface were lower than from soil with incorporated residues. The type of crop residue had no effect on the CH4 emissions, while higher N2O emissions were observed from serradella (leguminous) than from ryegrass, but only when the residues were left on the soil surface. The more intense soil reduction verified in the deeper soil layer (20 cm), as evidenced by higher contents of reduced metal species (Mn2+ and Fe2+), and the close relationship between CH4 emission and the DOC contents in the deeper layer indicated that the sub-surface layer was the main CH4 source of the flooded soil with incorporated crop residues. The adoption of management strategies in which crop residues are left on the soil surface is crucial to minimize soil CH4 and N2O emissions from irrigated rice fields. In these production systems, CH4 accounts for more than 90 % of the partial global warming potential (CH4+N2O) and, thus, should be the main focus of research.

Global warming in Amazonia: impacts and Mitigation

Global warming has potentially catastrophic impacts in Amazonia, while at the same time maintenance of the Amazon forest offers one of the most valuable and cost-effective options for mitigating climate change. We know that the El Niño phenomenon, caused by temperature oscillations of surface water in the Pacific, has serious impacts in Amazonia, causing droughts and forest fires (as in 1997-1998). Temperature oscillations in the Atlantic also provoke severe droughts (as in 2005). We also know that Amazonian trees die both from fires and from water stress under hot, dry conditions. In addition, water recycled through the forest provides rainfall that maintains climatic conditions appropriate for tropical forest, especially in the dry season. What we need to know quickly, through intensified research, includes progress in representing El Niño and the Atlantic oscillations in climatic models, representation of biotic feedbacks in models used for decision-making about global warming, and narrowing the range of estimating climate sensitivity to reduce uncertainty about the probability of very severe impacts. Items that need to be negotiated include the definition of "dangerous" climate change, with the corresponding maximum levels of greenhouse gases in the atmosphere. Mitigation of global warming must include maintaining the Amazon forest, which has benefits for combating global warming from two separate roles: cutting the flow the emissions of carbon each year from the rapid pace of deforestation, and avoiding emission of the stock of carbon in the remaining forest that can be released by various ways, including climate change itself. Barriers to rewarding forest maintenance include the need for financial rewards for both of these roles. Other needs are for continued reduction of uncertainty regarding emissions and deforestation processes, as well as agreement on the basis of carbon accounting. As one of the countries most subject to impacts of climate change, Brazil must assume the leadership in fighting global warming.

Local-scale spatial variation in diversity of social wasps in an Amazonian rain forest in Caxiuanã, Pará, Brazil (Hymenoptera, Vespidae, Polistinae)

Polistine wasps are important in Neotropical ecosystems due to their ubiquity and diversity. Inventories have not adequately considered spatial attributes of collected specimens. Spatial data on biodiversity are important for study and mitigation of anthropogenic impacts over natural ecosystems and for protecting species. We described and analyzed local-scale spatial patterns of collecting records of wasp species, as well as spatial variation of diversity descriptors in a 2500-hectare area of an Amazon forest in Brazil. Rare species comprised the largest fraction of the fauna. Close range spatial effects were detected for most of the more common species, with clustering of presence-data at short distances. Larger spatial lag effects could also be identified in some species, constituting probably cases of exogenous autocorrelation and candidates for explanations based on environmental factors. In a few cases, significant or near significant correlations were found between five species (of Agelaia, Angiopolybia, and Mischocyttarus) and three studied environmental variables: distance to nearest stream, terrain altitude, and the type of forest canopy. However, association between these factors and biodiversity variables were generally low. When used as predictors of polistine richness in a linear multiple regression, only the coefficient for the forest canopy variable resulted significant. Some level of prediction of wasp diversity variables can be attained based on environmental variables, especially vegetation structure. Large-scale landscape and regional studies should be scheduled to address this issue.

Perspectives in the use of carbon dioxide

The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

A FACTORIAL DESIGN APPLIED TO THE STUDY OF CHROMIUM TOXICITY ON THE GLUTATHIONE LEVELS OF Brachiaria brizantha AND Brachiaria ruziziensis SEEDLINGS

Chromium toxicity affects redox reactions within plant cells, generating detrimental reactive oxygen species. Glutathione is an antioxidant peptide and also a substrate for the production of phytochelatins, which are chelating peptides reported to mitigate Cr3+ toxicity in plants. In this study, Brachiaria brizantha (B. brizantha) and Brachiaria ruziziensis (B. ruziziensis) seedlings were evaluated for physiological responses and glutathione production following the addition of zero or 5 mg L-1 Cr3+ to the nutrient solution. Glutathione levels were determined by colorimetric analysis at 412 nm using 5,5'-dithio-bis(2-nitrobenzoic acid) as a chromophore reagent and recovery with glutathione reductase (with evaluations at days 10 and 20 of continuous growth). The assessments were carried out in a completely randomized design with 2 authentic replications, and arranged in a 23 factorial. Cr3+ caused an average increase of 0.76 mg g-1 in the initial glutathione content. However, by day 20 there was an average reduction of 3.63 mg g-1. Chromium-affected physiological detrimental responses, albeit detected in both species, were less-pronounced in B. ruziziensis, along with a much higher level of glutathione. This study indicates that B. ruziziensis has a greater tolerance for chromium toxicity than B. brizantha, and that glutathione is likely to be involved in the mitigation of chromium stress in B. ruziziensis.

Etiology of phomopsis root rot in soybean

In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

Effect of exercise on the caloric intake of breast cancer patients undergoing treatment

The purpose of this study was to examine the effects of an exercise intervention on the total caloric intake (TCI) of breast cancer patients undergoing treatment. A secondary purpose was to determine whether or not a relationship existed between changes in TCI, body fat composition (%BF), and fatigue during the study, which lasted 6 months. Twenty females recently diagnosed with breast cancer, scheduled to undergo chemotherapy or radiation, were assigned randomly to an experimental (N = 10) or control group (N = 10). Outcome measures included TCI (3-day food diary), %BF (skinfolds), and fatigue (revised Piper Fatigue Scale). Each exercise session was conducted as follows: initial cardiovascular activity (6-12 min), followed by stretching (5-10 min), resistance training (15-30 min), and a cool-down (approximately 8 min). Significant changes in TCI were observed among groups (F1,18 = 8.582; P = 0.009), at treatments 2 and 3, and at the end of the study [experimental (1973 ± 419), control (1488 ± 418); experimental (1946 ± 437), control (1436 ± 429); experimental (2315 ± 455), control (1474 ± 294), respectively]. A significant negative correlation was found (Spearman rho(18) = -0.759; P < 0.001) between TCI and %BF and between TCI and fatigue levels (Spearman rho(18) = -0.541; P = 0.014) at the end of the study. In conclusion, the results of this study suggest that an exercise intervention administered to breast cancer patients undergoing medical treatment may assist in the mitigation of some treatment side effects, including decreased TCI, increased fatigue, and negative changes in body composition.

Is sustainability certification for biochar the answer to environmental risks?

Biochar has the potential to make a major contribution to the mitigation of climate change, and enhancement of plant production. However, in order for biochar to fulfill this promise, the industry and regulating bodies must take steps to manage potential environmental threats and address negative perceptions. The potential threats to the sustainability of biochar systems, at each stage of the biochar life cycle, were reviewed. We propose that a sustainability framework for biochar could be adapted from existing frameworks developed for bioenergy. Sustainable land use policies, combined with effective regulation of biochar production facilities and incentives for efficient utilization of energy, and improved knowledge of biochar impacts on ecosystem health and productivity could provide a strong framework for the development of a robust sustainable biochar industry. Sustainability certification could be introduced to provide confidence to consumers that sustainable practices have been employed along the production chain, particularly where biochar is traded internationally.

Inventário de emissão de fontes veiculares da Região Metropolitana de Campinas, São Paulo

The degradation of air quality in great urban centers is noted by frequent critical episodes of air pollution and public health issues, and vehicles are a great source of pollutant emissions, mainly derived from combustion processes. A database is needed to direct mitigation of emissions. The main objective of this work is to present it as an emissions inventory. The results show that vehicular sources of CO, HC and NOx represent over 75% of total emissions in the MRC. Besides, the proposed methodology presented results consistent with the literature

Química Sem Fronteiras: o desafio da energia

Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great effort to develop "second-generation" technologies to produce methanol, ethanol, butanol, biodiesel, biogas (methane), bio-oils, syngas and synthetic fuels from lower grade renewable feedstocks such as lignocellulosic materials whose consumption would not interfere with the rather sensitive issues of food security. Advanced fermentation processes are envisaged as "third generation" technologies and these are primarily linked to the use of algae feedstocks as well as other organisms that could produce biofuels or simply provide microbial biomass for the processes listed above. Due to the complexity and cost of their production chain, "third generation" technologies usually aim at high value added biofuels such as biojet fuel, biohydrogen and hydrocarbons with a fuel performance similar to diesel or gasoline, situations in which the use of genetically modified organisms is usually required. In general, the main challenges in this field could be summarized as follows: (a) the need for prospecting alternative sources of biomass that are not linked to the food chain; (b) the intensive use of green chemistry principles in our current industrial activities; (c) the development of mature technologies for the production of second and third generation biofuels; (d) the development of safe bioprocesses that are based on environmentally benign microorganisms; (e) the scale-up of potential technologies to a suitable demonstration scale; and (f) the full understanding of the technological and environmental implications of the food vs. fuel debate. On the basis of these, the main objective of this article is to stimulate the discussion and help the decision making regarding "energy security" issues and their challenges for modern society, in such a way to encourage the participation of the Brazilian Chemistry community in the design of a road map for a safer, sustainable and prosper future for our nation.

Occurrence and damages of Danothrips trifasciatus (Thysanoptera, Thripidae) on Calophyllum brasiliense (Clusiaceae) in Brazil

Occurrence and damages of Danothrips trifasciatus (Thysanoptera: Thripidae) on Calophyllum brasiliense (Clusiaceae) in Brazil. Danothrips trifasciatus Sakimura, 1975 (Thysanoptera, Thripidae) is recorded for the first time in Brazil, in the municipality of Garça, São Paulo state. Individuals were collected in April 2011 damaging young leaves of guanandi, Calophyllum brasiliense Cambess. (Clusiaceae), forest species of increasing importance in Brazil. Future studies involving aspects on biology and population dynamics of the thrips in this plant species need to be carried out, in order to establish its potential economic importance to guanandi.

Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index), electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

Modulatory activity of antioxidants against the toxicity of Rifampicin in vivo

The World Health Organization (WHO) has shown concern about the burden of tuberculosis in the developing countries. Even though rifampicin is an effective drug in the management of tuberculosis, it has been documented to have some toxic effects in humans. Therefore, this study intends to investigate the modulatory effect of vitamins C and E on the hepatotoxicity, sperm quality and brain toxicity of Rifampicin. Forty Wistar albino rats were used, 10 animals per group. Group 1 animals received 0.3 mL of distilled water, the Group 2 animals received the therapeutic dose of rifampicin, Group 3 animals received therapeutic doses of rifampicin plus vitamin E, while Group 4 received therapeutic doses of rifampicin and vitamin C. The administration was performed orally during three months; the animals were sacrificed by cervical dislocation at the end of that period. Blood samples were collected and liver function and lipid profile was analyzed using fully automated clinical chemistry device. The liver, brain and reproductive organs underwent histopathological examination. Sperm samples were collected from the epididymis to achieve count and motility and morphological analysis. Results showed rifampicin alone to raise (p < 0.05) liver function enzymes (Aspartate amino transferase [AST], Serum alanine amino transferase [ALT] and Total Bilirubin) when compared with controls. While the vitamin E treated group showed remarkable protection, the vitamin C treated group showed questionable protection against the rifampicin induced liver damage. Sperm count results showed an important (p < 0.05) increase in the sperm quality in vitamin E and C treated groups. However, the vitamin E plus Rifampicin treated group showed increased lipid peroxidation. The histopathological findings revealed structural damages by rifampicin in liver, brain and epididymis while some remarkable architectural integrity was observed in the antioxidant-treated groups. It can be concluded that vitamin E or C improved sperm quality and protected against the brain damage caused by rifampicin. Moreover, vitamin E demonstrated remarkable hepatoprotection against rifampicin induced damage while vitamin C shows a questionable hepatoprotection.

Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil

INTRODUCTION: The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. METHODS: Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-β-lactamase (MBL) genes, and clonal relationship among isolates. RESULTS: A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. CONCLUSIONS: These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.

Pandemic influenza A (H1N1) 2009: epidemiological analysis of cases in a tropical/semi-arid region of Brazil

IntroductionThe year 2009 marked the beginning of a pandemic caused by a new variant of influenza A (H1N1). After spreading through North America, the pandemic influenza virus (H1N1) 2009 spread rapidly throughout the world. The aim of this study was to describe the clinical and epidemiological characteristics of cases of pandemic influenza in a tropical/semi-arid region of Brazil.MethodsA retrospective study analyzed all suspected cases of pandemic influenza (H1N1) 2009 reported in the Ceará State through the National Information System for Notifiable Diseases during the pandemic period between 28 April, 2009 and November 25, 2010.ResultsA total of 616 suspected cases were notified, 58 (9.4%) in the containment phase and 558 (90.6%) in the mitigation phase. Most cases were of affected young people resident in the City of Fortaleza, the largest urban center in the State of Ceará. The most frequent symptoms presented by the cases with confirmed infection were fever, cough, myalgia, arthralgia, and nasal congestion. Mortality rate was 0.0009/1,000 inhabitants and lethality was 5.6%. Deaths were observed only in the mitigation phase. Mortality rates were similar for both sexes but were higher in the age group under 5 years.ConclusionsThe study suggests that the influenza A (H1N1) pandemic in this tropical/semi-arid region had a lower magnitude when compared to states in the Southern and Southeastern regions of Brazil.