Biocombustibles en Argentina, Brasil y Colombia : Avances y limitaciones

Los biocombustibles introducen espacios agrícolas en la producción energética. Luego modifican la gobernanza de las redes energéticas y de los territorios productivos. Las principales críticas a los biocombustibles se dirigen a su producción a partir de cultivos tradicionales, pero interesa preguntarse también sobre la sostenibilidad de su producción a partir de cultivos alternativos, que no competirían con los cultivos alimentarios, puesto que se ubicarían en regiones agrícolas marginales. El texto trata sobre las producciones de biocombustibles de los países de América del Sur, en sus contextos internacionales, nacionales y locales. Se profundiza la mirada sobre Argentina, Brasil y Colombia, líderes continentales en el sector. Se analizan la evolución del mercado energético, los actores involucrados y las políticas implementadas. A otra escala, se plantea la puesta en marcha de las cadenas de biocombustibles alternativos.

Las nuevas medidas agroenergéticas mexicanas: un modelo microeconométrico para la evaluación de su impacto sobre los ecosistemas naturales en los estados de Hidalgo, Querétaro y Tamaulipas (México)

La ley para la Promoción y Desarrollo de Biocombustibles aprobada en México en 2007 permite la producción de bioetanol y biodiesel. Esta producción puede entrar en conflicto con la producción de alimentos y con los ecosistemas naturales y en esta tesis se desarrolla un modelo microeconométrico que puede servir de base para anticiparse a esos conflictos y para diseñar medidas de política agraria orientadas a potenciar la compatibilidad de la producción de biocombustibles con la de alimentos y con la conservación de los ecosistemas naturales. A partir de una muestra de explotaciones de tres Estados de México – Hidalgo, Querétaro y Tamaulipas- y de un modelo logit multinomial mixto, se estima la elasticidad de la superficie destinada a cultivos alimentarios respecto a cambios en los márgenes económicos de los cultivos agroenergéticos. Esa elasticidad resulta ser significativa. Mostramos que su estimación es útil para anticipar cambios en la superficie destinada a los cultivos alimentarios y a los forestales. Se evalúa el impacto de varios escenarios relativos a los márgenes brutos de los cultivos sobre las decisiones de los agricultores y se muestra la utilidad del modelo para detectar tendencias de cambio a largo plazo en la alternativa de cultivos, incluyendo los forestales. ABSTRACT The Law for the Promotion and Development of Biofuels in Mexico adopted in 2007 allows for the production of bioethanol and biodiesel. This production may conflict with food production and natural ecosystems and this thesis develops a microeconometric model that can serve as a basis to anticipate such conflicts and to implement agricultural policy measures designed to enhance the compatibility of biofuels with production food and natural ecosystems conservation. We estimate the elasticity of the area devoted to food crops with respect to changes in economic margins of energy crops, using a sample of farms in three states of Mexico - Hidalgo, Queretaro and Tamaulipas - , and a multinomial mixed logit model. We found that this elasticity is significant. And we show how it can be useful to anticipate changes in area under food crops and forests. The impact of various scenarios about gross margins on farmers' decisions is assessed and it is shown the usefulness of the model to detect trends of long-term change in the crops area, including forests.

Urbanization, socio-economic changes and population growth in Brazil: dietary shifts and environmental implications.

Population growth, economic globalization, improving living standards and urbanization are causing important changes in the global food system and modifying the dietary habits in many parts of the world (Molden, 2007; Godfray et al., 2010). The nutritional transition (linked to the development of countries and the increasing wealth of its population) implies a shift away from traditional staple food such as roots and tuber vegetables and a rise in consumption of meat and milk products, refined and processed foods, as well as sugars, oils and fats (Ambler-Edwards et al., 2009). The contemporary food system puts significant pressure on natural resources, especially on land and water, because the growing food demand pushes the agricultural frontier beyond, causing large impacts on ecosystems (Ambler-Edwards et al. 2009: 11-18). Also, the trend towards richer diets in animal proteins and processed food adds further pressure on the environment, since it requires larger amount of water and land to be produced (Allan, 2011; Mekonnen and Hoekstra, 2012).

Approach to the potential production of giant reed in surplus saline lands of Spain

Growing energy crops on marginal land has been promoted as a way of ensuring that biomass production involves an acceptable and sustainable use of land. Saline and saline-prone agricultural lands represent an opportunity for growing energy crops avoiding the displacement of food production and contributing to restoration of degraded land. Giant reed (Arundo donax L.) is a perennial grass that has been proposed as a promising energy crop for lignocellulosic biomass production while its tolerance to salinity has been proved. In this work, the identification of surplus saline lands that could be irrigated with saline waters for growing tolerant-energy crops (giant reed) in the mainland of Spain and the assessment of the agronomically attainable yield in these limiting growing conditions were undertaken. To this purpose, a GIS analysis was conducted using geodatabases related to saline areas, agro-climatic conditions, irrigation water requirements, agricultural land availability, restrictions regarding the range of electrical conductivity tolerated by the crop, competition with agro-food crops and irrigation water provisions. According to the approach developed, the irrigated and saline agricultural area available and suitable for biomass production from giant reed amounted up to 34 412 ha. The agronomically attainable yield in these limiting conditions was estimated at 12.7 – 22.2 t dm ha−1 yr−1 and the potential production of lignocellulosic biomass, 597 338 t dm yr−1. The methodology followed in this study can be applied to other target regions; it allows the identification of this type of marginal lands, where salinity-tolerant plant species could be grown for bioenergy purposes, avoiding competition with agro-food crops, and where soil restoration measurements should be undertaken.

Compromised disease resistance in saponin-deficient plants

Saponins are glycosylated plant secondary metabolites found in many major food crops [Price, K. R., Johnson, I. T. & Fenwick, G. R. (1987) CRC Crit. Rev. Food Sci. Nutr. 26, 27–133]. Because many saponins have potent antifungal properties and are present in healthy plants in high concentrations, these molecules may act as preformed chemical barriers to fungal attack. The isolation of plant mutants defective in saponin biosynthesis represents a powerful strategy for evaluating the importance of these compounds in plant defense. The oat root saponin avenacin A-1 fluoresces under ultraviolet illumination [Crombie, L., Crombie, W. M. L. & Whiting, D. A. (1986) J. Chem. Soc. Perkins 1, 1917–1922], a property that is extremely rare among saponins. Here we have exploited this fluorescence to isolate saponin-deficient (sad) mutants of a diploid oat species, Avena strigosa. These sad mutants are compromised in their resistance to a variety of fungal pathogens, and a number of lines of evidence suggest that this compromised disease resistance is a direct consequence of saponin deficiency. Because saponins are widespread throughout the plant kingdom, this group of secondary metabolites may have general significance as antimicrobial phytoprotectants.

Fumonisins and Alternaria alternata lycopersici toxins: sphinganine analog mycotoxins induce apoptosis in monkey kidney cells.

Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell homeostasis were investigated in African green monkey kidney cells (CV-1) by assessing the appearance of apoptosis, cell cycle regulation, and putative components of signal transduction pathways involved in apoptosis. Structurally, these mycotoxins resemble the sphingoid bases, sphingosine and sphinganine, that are reported to play critical roles in cell communication and signal transduction. The addition of fumonisin B1 or AAL toxin, TA, to CV-1 cells induced the stereotypical hallmarks of apoptosis, including the formation of DNA ladders, compaction of nuclear DNA, and the subsequent appearance of apoptotic bodies. Neither mycotoxin induced cell death, DNA ladders, or apoptotic bodies in CV-1 cells expressing simian virus 40 large T antigen (COS-7) at toxin concentrations that readily killed CV-1 cells. Fumonisin B1 induced cell cycle arrest in the G1 phase in CV-1 cells but not in COS-7 cells. AAL toxin TA did not arrest cell cycle progression in either cell line. The induction of apoptosis combined with the widespread presence of these compounds in food crops and animal feed identifies a previously unrecognized health risk to humans and livestock. These molecules also represent a new class of natural toxicants that can be used as model compounds to further characterize the molecular and biochemical pathways leading to apoptosis.

Gaseificação de microalgas: estudo termogravimétrico e modelagem matemática do processo em reator solar.

Devido ao esgotamento de recursos não renováveis e o aumento das preocupações sobre as alterações climáticas, a produção de combustível renovável a partir de microalgas continua a atrair muita a atenção devido ao seu potencial para taxas rápidas de crescimento, alto teor de óleo, capacidade de crescer em cenários não convencionais e a neutralidade de carbono, além de eliminar a preocupação da disputa com as culturas alimentares. Em virtude disso, torna-se importante o desenvolvimento de um processo de conversão das microalgas em gás combustível, em destaque o gás de síntese. Visando essa importância, estudou-se a reação de gaseificação da microalga Chlorella vulgaris através de experimentos de análise termogravimétrica para estimar os parâmetros cinéticos das reações e através da simulação de um modelo matemático dinâmico termoquímico do processo usando equações de conservação de massa e energia acoplados a cinética de reação. Análises termogravimétricas isotérmicas e dinâmicas foram realizadas usando dois diferentes tipos de modelos cinéticos: isoconversionais e reações paralelas independentes (RPI). Em ambos os modelos, os valores dos parâmetros cinéticos estimados apresentaram bons ajustes e permaneceram dentro daqueles encontrados na literatura. Também foram analisados os efeitos dos parâmetros cinéticos do modelo RPI sobre a conversão da microalga no intuito de observar quais mais se pronunciavam diante a variação de valores. Na etapa de simulação do sistema controlado pelo reator solar, o modelo matemático desenvolvido foi validado por meio da comparação dos valores de temperatura e concentrações de produtos obtidos medidos experimentalmente pela literatura, apresentando boa aproximação nos valores e viabilizando, juntamente com a etapa experimental de termogravimetria, a produção de gás de síntese através da gaseificação da microalga Chlorella vulgaris.

The EU regime on biofuels in transport: Still in search of sustainability. Egmont Paper No. 68, July 2014

Like other regions of the world, the EU is developing biofuels in the transport sector to reduce oil consumption and mitigate climate change. To promote them, it has adopted favourable legislation since the 2000s. In 2009 it even decided to oblige each Member State to ensure that by 2020 the share of energy coming from renewable sources reached at least 10% of their final consumption of energy in the transport sector. Biofuels are considered the main instrument to reach that percentage since the development of other alternatives (such as hydrogen and electricity) will take much longer than expected. Meanwhile, these various legislative initiatives have driven the production and consumption of biofuels in the EU. Biofuels accounted for 4.7% of EU transport fuel consumption in 2011. They have also led to trade and investment in biofuels on a global scale. This large-scale expansion of biofuels has, however, revealed numerous negative impacts. These stem from the fact that first-generation biofuels (i.e., those produced from food crops), of which the most important types are biodiesel and bioethanol, are used almost exclusively to meet the EU’s renewable 10% target in transport. Their negative impacts are: socioeconomic (food price rises), legal (land-grabbing), environmental (for instance, water stress and water pollution; soil erosion; reduction of biodiversity), climatic (direct and indirect land-use effects resulting in more greenhouse gas emissions) and public finance issues (subsidies and tax relief). The extent of such negative impacts depends on how biofuel feedstocks are produced and processed, the scale of production, and in particular, how they influence direct land use change (DLUC) and indirect land use change (ILUC) and the international trade. These negative impacts have thus provoked mounting debates in recent years, with a particular focus on ILUC. They have forced the EU to re-examine how it deals with biofuels and submit amendments to update its legislation. So far, the EU legislation foresees that only sustainable biofuels (produced in the EU or imported) can be used to meet the 10% target and receive public support; and to that end, mandatory sustainability criteria have been defined. Yet they have a huge flaw. Their measurement of greenhouse gas savings from biofuels does not take into account greenhouse gas emissions resulting from ILUC, which represent a major problem. The Energy Council of June 2014 agreed to set a limit on the extent to which firstgeneration biofuels can count towards the 10% target. But this limit appears to be less stringent than the ones made previously by the European Commission and the European Parliament. It also agreed to introduce incentives for the use of advanced (second- and third-generation) biofuels which would be allowed to count double towards the 10% target. But this again appears extremely modest by comparison with what was previously proposed. Finally, the approach chosen to take into account the greenhouse gas emissions due to ILUC appears more than cautious. The Energy Council agreed that the European Commission will carry out a reporting of ILUC emissions by using provisional estimated factors. A review clause will permit the later adjustment of these ILUC factors. With such legislative orientations made by the Energy Council, one cannot consider yet that there is a major shift in the EU biofuels policy. Bolder changes would have probably meant risking the collapse of the high-emission conventional biodiesel industry which currently makes up the majority of Europe’s biofuel production. The interests of EU farmers would have also been affected. There is nevertheless a tension between these legislative orientations and the new Commission’s proposals beyond 2020. In any case, many uncertainties remain on this issue. As long as solutions have not been found to minimize the important collateral damages provoked by the first generation biofuels, more scientific studies and caution are needed. Meanwhile, it would be wise to improve alternative paths towards a sustainable transport sector, i.e., stringent emission and energy standards for all vehicles, better public transport systems, automobiles that run on renewable energy other than biofuels, or other alternatives beyond the present imagination.

A commentary on the impacts of metals and metalloids in the environment upon the metabolism of drugs and chemicals

The salient feature of metals is that unlike organic compounds they do not degrade in the environment and barely move from one environmental matrix to another. Human interventions take these compounds from their stable and non-bioavailable geological matrix into situations of biological accessibility. Studies in the 1970s and the 1980s of metal bioavailability and impacts of metals and metalloids were driven by the process of abatement of lead in the environment. Humans have clear and identifiable sources of exposure from fuels, food and leaded water pipes to lead. Interventions started at that time have dramatically lowered human lead exposure. Attention has now shifted to other metals, in particular, cadmium, which has seen increasing use. It is generally accepted that food crops grown on cadmium containing soils or soils naturally rich in this metal are the major source of exposure to humans other than exposure from smoking of cigarettes. This mini-review gives a summary and commentary on early studies on effects of lead on haem metabolism that provide us the clue to why investigations of the impacts of other toxic heavy metals and metalloids such as cadmium and arsenic on different human cytochrome P450 forms have become of great interest at the current time. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

The spatial pattern of child growth in Papua New Guinea

Child growth in PNG shows strong regional differences, with highlands children being generally shorter but stockier than those from lowland areas. Differences in diet, socioeconomic status and local subsistence agriculture were found to be important predictors of child growth. All variables indicating higher socioeconomic status were correlated with better growth, as was a high consumption of imported and local high quality foods such as cereals, legumes, tinned fish or meat and fresh fish. Differences in subsistence explained between 25% and 50% of the geographical variation in growth. Child growth was better in systems based on cassava and sweet potato, and worse in those where banana, sago and taro are staples. The cultivation of all major cash crops and sales of fish and food crops improved child growth. Birth weights show similar patterns to those observed in child growth. The implications of these findings for possible interventions are discussed.

Nanoporous solid acid and base catalysts for sustainable biofuels production

Dwindling fossil fuel reserves, and growing concerns over CO2 emissions and associated climate change, are driving the quest for renewable feedstocks to provide alternative, sustainable fuel sources. Catalysis has a rich history of facilitating energy efficient, selective molecular transformations, and in a post-petroleum era will play a pivotal role in overcoming the scientific and engineering barriers to economically viable, and sustainable, biofuels derived from renewable resources. The production of second generation biofuels, derived from biomass sourced from inedible crop components, e.g. agricultural or forestry waste, or alternative non-food crops such as Switchgrass or Jatropha Curcas that require minimal cultivation, necessitate new heterogeneous catalysts and processes to transform these polar and viscous feedstocks [1]. Here we show how advances in the rational design of nanoporous solid acids and bases, and their utilisation in novel continuous reactors, can deliver superior performance in the energy-efficient esterification and transesterification of bio-oil components into biodiesel [2-4]. Notes: [1] K. Wilson, A.F. Lee, Cat. Sci. Tech. 2012 ,2, 884. [2] J. Dhainaut, J.-P. Dacquin, A. F. Lee, K. Wilson, Green Chem. 2010 , 12, 296. [3] C. Pirez, J.-M. Caderon, J.-P. Dacquin, A.F. Lee, K. Wilson, ACS Catal. 2012 , 2, 1607. [4] J.J. Woodford, J.-P. Dacquin, K. Wilson, A.F. Lee, Energy Environ. Sci. 2012 , 5, 6145.

Determinação da composição química de quatro variedades de feijão caupi (Vigna unguiculata L. Walp) cultivadas em solo potiguar

The cowpea (Vigna unguiculata L. Walp) is a major food crops in northeastern Brazil. In Rio Grande do Norte, the cowpea, vigna beans or cowpea, as it is known, has great socioeconomic importance as a source of nutrients in food, with great emphasis among agricultural products. To improve productivity and resistance to pests, two cultivars were developed exclusively by EMPARN (Agricultural Research Corporation of Rio Grande do Norte), for breeding. The samples were provided by EMPARN, two improved (Potiguar and Laugh year) and two landraces (Rib of beef and Canapu). The seeds were ground and made into flour samples and the determination of moisture and ash by graviméticos methods, lipids by Soxhlet extraction, fibers with determiner fiber, carbohydrates by difference and minerals by ICP-OES were performed except the match analyzed by UVvis. The results showed a high fiber content (55.55% and 55.32% and 50.04% improved samples and 50.32% creole samples) and protein (25.52% and 25.27% improved and 27 samples, 23% and 24.99% creole samples). Comparing the results of the mineral content, the improved cultivars stood out in relation to Ca, Co, P, Mg, Mo and Na. Creole cultivars showed better results for Cu, Cr (low), Fe, Mn, Ni, K and Zn. The results will be important in future nutritional research and to build a table of Brazilian chemical composition of foods.

Exploring the potential of cassava in promoting agricultural growth in Nigeria

Cassava is one of the major food crops in Nigeria, with multiple uses from human consumption to industrial applications. This study explores the potential of cassava in Nigerian agriculture based on a review of cassava development policies; performs a trend analysis of the cultivation area, production, productivity, and real price of cassava and other competing crops for the period 1961–2013; identifies the sources of growth in production; and examines the production constraints at the local level based on a survey of 315 farmers/processors and 105 marketers from Delta State. The results revealed that several policies and programmes were implemented to develop the cassava sector with mixed outcomes. Although cassava productivity grew at 1.5% per annum (p.a.) during the post-structural adjustment programme period (1993–2013), its real price declined at a rate of 3.5% p.a. The effect of yield is the main source of growth in production, contributing 76.4% of the total growth followed by the area effect (28.2%). The cassava sector is constrained by inadequate market infrastructure, processing facilities, and lack of information and unstable prices at the local level. The widespread diffusion of improved tropical manioc selection technologies and investments in market and marketing infrastructure, processing technologies, irrigation/water provision and information dissemination are recommended to enhance the potential of the cassava sector to support agricultural growth in Nigeria.

Bridging Perspectives

People’s ability to change their social and economic circumstances may be constrained by various forms of social, cultural and political domination. Thus to consider a social actor’s particular lifeworld in which the research is embedded assists in the understanding of how and why different trajectories of change occur or are hindered and how those changes fundamentally affect livelihood opportunities and constraints. In seeking to fulfill this condition this thesis adopted an actor-oriented approach to the study of rural livelihoods. A comprehensive livelihoods study requires grasping how social reality is being historically constituted. That means to understand how the interaction of modes of production and symbolical reproduction produces the socio-space. Research is here integrated to action through the facilitation of farmer groups. The overall aim of the groups was to prompt agency, as essential conditions to build more resilient livelihoods. The smallholder farmers in the Mabalane District of Mozambique are located in a remote semi-arid area. Their livelihoods customarily depend at least as much on livestock as on (mostly) rain-fed food crops. Increased climate variability exerts pressure on the already vulnerable production system. An extensive 10-month duration of participant observation divided into 3 periods of fieldwork structured the situated multi-method approach that drew on a set of interview categories. The actor-oriented appraisal of livelihoods worked in building a mutually shared definition of the situation. This reflection process was taken up by the facilitation of the farmer groups, one in Mabomo and one in Mungazi, which used an inquiry iteratively combining individual interviews and facilitated group meetings. Integration of action and reflection was fundamental for group constitution as spaces for communicative action. They needed to be self-organized and to achieve understanding intersubjectively, as well as to base action on cooperation and coordination. Results from this approach focus on how learning as collaboratively generated was enabled, or at times hindered, in (a) selecting meaningful options to test; (b) in developing mechanisms for group functioning; and (c) in learning from steering the testing of options. The study of livelihoods looked at how the different assets composing livelihoods are intertwined and how the increased severity of dry spells is contributing to escalated food insecurity. The reorganization of the social space, as households moved from scattered homesteads to form settlements, further exerts pressure on the already scarce natural resource-based livelihoods. Moreover, this process disrupted a normative base substantiating the way that the use of resources is governed. Hence, actual livelihood strategies and response mechanisms turn to diversification through income-generating activities that further increase pressure on the resource-base in a rather unsustainable way. These response mechanisms are, for example, the increase in small-livestock keeping, which has easier conversion to cash, and charcoal production. The latter results in ever more precarious living and working conditions. In the majority of the cases such responses are short-term and reduce future opportunities in a downward spiral of continuously decreasing assets. Thus, by indicating the failure of institutions in the mediation of smallholders’ adaptive capabilities, the livelihood assessment in Mabomo and Mungazi sheds light on the complex underlying structure of present day social vulnerability, linking the macro-context to the actual situation. To assist in breaking this state of “subordination”, shaped by historical processes, weak institutions and food insecurity, the chosen approach to facilitation of farmer groups puts farmer knowledge at the center of an evolving process of intersubjective co-construction of knowledge towards emancipation.

Salicaceae Endophytes: Growth Promotion Potential in Rice (Oryza sativa L.) and Maize (Zea mays L.) and Bio-Control of Plant Pathogen

Thesis (Ph.D.)--University of Washington, 2016-08