Subsidios y Estrategias de Producción Campesina : el caso de Casas Blancas, México

El análisis del metabolismo social brinda los elementos para comprender las interacciones que mantiene la sociedad con la naturaleza. Bajo esta perspectiva este artículo analiza a diferentes las relaciones sociales y económicas de tres sistemas de manejo de recursos naturales (SMRN) en una comunidad rural de México. Se construyó una tipología de sistemas basada en los componentes productivos y las instituciones locales asociadas a estos. Cada sistema se analizó considerando tres tipos de flujos: i) flujos monetarios provenientes de los subsidios; ii) flujos materiales de la producción agrícola y pecuaria y iii) flujos de mano de obra. Se hizo una caracterización a tres escalas: componente productivo, sistema y comunidad. Los resultados obtenidos muestran que existe una interacción negativa entre los subsidios y la diversificación productiva y una interacción positiva entre el número de componentes y la demanda de mano de obra. Se asocian los subsidios de plantaciones comerciales y las formas de organización social con la disminución de superficie agrícola y aumento de la superficie forestal. Estos resultados permiten conocer los factores internos y externos del sistema que afectan las estrategias campesinas de manejo de recursos naturales vinculadas con la autosuficiencia alimentaria.Social metabolism analysis gives the conceptual basis to understand interactions between society and nature. Beyond this perspective and the systems theory, this article analyzes at different scales social and economic relations of three natural resources management systems in a rural community from Mexico. A system typology was constructed based on the productive components and local institutions. Each system was studied considering three types of fluxes: i) monetary fluxes from subsidies; ii) material fluxes from agricultural and livestock production and iii) labour fluxes. A characterization of these fluxes was made at three scales: i) productive component (maize, livestock and forest); ii) parcels (system) and iii) community. The results showed that there is a negative interaction between subsidies and productive diversification and a positive interaction between number of components and labour demand. Subsidies for commercial forest plantations and social organization are associated with the diminution of agricultural area and an increase of forest cultivated surface. These results had shown some of the internal and external factors that affect peasant strategies of natural resources management and its implications with self sufficiency

Fuelwood use patterns in Rural Mexico: a critique to the conventional energy transition model

This article presents an historical account of patterns of household fuelwood use in Mexico from 1960 until the present. The results of scenarios outlining the likely evolution of future fuelwood use according to different socio-demographic and technological variables are offered up to 2030 along with the expected environmental impacts. Mexico is an interesting case as it went from importing oil to becoming an oil-exporting country during the historical period under analysis and the use of liquefied petroleum gas (LPG) intensified in the residential sector. However, rather than exhibiting a sharp decline in fuelwood use, as would be expected from the energy transition model, we observe that fuelwood use has remained almost constant for more than 40 years. In fact, rather than completely switching to LPG, a large portion of rural and small-town households adopted a fuel-stacking strategy, combining both fuels on a long-term basis. We conclude by examining the implications of the current patterns of fuelwood use and fuel-stacking in terms of future fuelwood consumption, numbers of users and emissions of greenhouse gases.Este artículo presenta un repaso histórico a las pautas de consumo de leña en los hogares mexicanos entre 1960 y la actualidad. Muestra también algunas proyecciones de consumo hasta el año 2030 calculadas en función de algunas variables sociodemográficas y tecnológicas, y se estiman sus posibles impactos ambientales. El caso de México tiene interés ya que el país pasó durante el periodo analizado de ser importador de petróleo a ser exportador de ese recurso energético, al mismo tiempo que el consumo de gas licuado de petróleo (LPG) se intensificaba en los hogares. Pese a ello, en lugar de producirse una caída brusca en el consumo de leña como predice el modelo tradicional de transición energética, observamos que dicho consumo se ha mantenido bastante estable durante los últimos cuarenta años. De hecho, una parte muy considerable de los hogares rurales y de las pequeñas ciudades, en lugar de saltar al uso de LPG, han adoptado una estrategia de uso múltiple que combina el uso de ambos combustibles en el largo plazo. El artículo termina analizando las implicaciones de los patrones de uso de la leña y de la estrategia de su uso múltiple para el futuro, en términos de consumo, de número de usuarios y de emisiones de gases de efecto invernadero

Subsidios y Estrategias de Producción Campesina: el caso de Casas Blancas, México

El análisis del metabolismo social brinda los elementos para comprender las interacciones que mantiene la sociedad con la naturaleza. Bajo esta perspectiva este artículo analiza a diferentes las relaciones sociales y económicas de tres sistemas de manejo de recursos naturales (SMRN) en una comunidad rural de México. Se construyó una tipología de sistemas basada en los componentes productivos y las instituciones locales asociadas a estos. Cada sistema se analizó considerando tres tipos de flujos: i) flujos monetarios provenientes de los subsidios; ii) flujos materiales de la producción agrícola y pecuaria y iii) flujos de mano de obra. Se hizo una caracterización a tres escalas: componente productivo, sistema y comunidad. Los resultados obtenidos muestran que existe una interacción negativa entre los subsidios y la diversificación productiva y una interacción positiva entre el número de componentes y la demanda de mano de obra. Se asocian los subsidios de plantaciones comerciales y las formas de organización social con la disminución de superficie agrícola y aumento de la superficie forestal. Estos resultados permiten conocer los factores internos y externos del sistema que afectan las estrategias campesinas de manejo de recursos naturales vinculadas con la autosuficiencia alimentaria.Sistemas campesinos, subsidios, mano de obra, políticas, México.

Potential use of pruning-residues from avocado trees as energy input in rural communities

The global need to transition to renewable and decentralized systems entails agricultural systems as producers of residual biomass. Avocado trees (Persea americana Mill.) are one of the main woody crops cultivated in Mexico, with over 150,000 hectares grown in the country. The aim of the present study is to evaluate the use of avocado pruning residues as an energy input, focusing on the revalorization of biomass and the generation of economic benefits for small producers in the region. For that purpose, we developed allometric equations to calculate biomass availability from pruning residues, evaluated their thermochemical properties, and proposed technological alternatives for their energy use. Two allometric equations for pruning residues as a function of tree height and crown diameter were obtained: one for light and minor maintenance pruning (R2 = 0.63) and one for rejuvenation pruning (R2 = 0.86). From these equations, we estimate the mean amount of biomass generated from light and rejuvenation pruning to be 42.7 and 25.1 kg per tree and year, respectively, which amounts to 1324 and 780 kg ha−1 DM (dry matter), with an energy potential of 26.2 and 15.4 GJ ha−1. The thermochemical analysis shows that a higher proportion of leaves generates a higher ash content, which reduces the quality of the residues as a fuel. Avocado pruning residues have high potential for energy use and could be implemented in the industrial and residential sectors, generating a complementary source of income for producers.Fil: Tauro, Raúl. Universidad Nacional Autónoma de México; MéxicoFil: Velázquez Martí, Borja. Universidad Politécnica de Valencia; EspañaFil: Manrique, Silvina Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Ricker, Martín. Universidad Nacional Autonoma de Mexico. Facultad de Ciencias; MéxicoFil: Martínez Bravo, René. Universidad Nacional Autónoma de México; MéxicoFil: Ruiz García, Víctor. Universidad Nacional Autónoma de México; MéxicoFil: Ramos Vargas, Saraí. Universidad Nacional Autónoma de México; MéxicoFil: Masera, Omar Raul. Universidad Nacional Autónoma de México; MéxicoFil: Soria González, José A.. Universidad Michoacana de San Nicolás de Hidalgo. Facultad de Ingeniería en Tecnología de la Madera; MéxicoFil: Armendariz, Cynthia. Universidad Nacional Autónoma de México; Méxic

Primeras evidencias de recuperación de hígados afectados por hepatotoxinas producidas por cianobacterias presentes en el Río de La Plata

En este trabajo se analizaron mediante diferentes técnicas histopatológicas hígados de ratones a los que se administró dosis letales de 100 μg/Kg y dosis subletales de 25 μg/K. Los hígados de estos animales se analizaron con técnicas histológicas.Facultad de Ciencias Exacta

Agriculture, Forestry and Other Land Use (AFOLU)

Agriculture, Forestry, and Other Land Use (AFOLU) is unique among the sectors considered in this volume, since the mitigation potential is derived from both an enhancement of removals of greenhouse gases (GHG), as well as reduction of emissions through management of land and livestock (robust evidence; high agreement). The land provides food that feeds the Earth’s human population of ca. 7 billion, fibre for a variety of purposes, livelihoods for billions of people worldwide, and is a critical resource for sustainable development in many regions. Agriculture is frequently central to the livelihoods of many social groups, especially in developing countries where it often accounts for a significant share of production. In addition to food and fibre, the land provides a multitude of ecosystem services; climate change mitigation is just one of many that are vital to human well-being (robust evidence; high agreement). Mitigation options in the AFOLU sector, therefore, need to be assessed, as far as possible, for their potential impact on all other services provided by land. [Section 11.1

Assessment of Pellets from Three Forest Species: From Raw Material to End Use

This study aimed to evaluate and compare the relationship between chemical properties, energy efficiency, and emissions of wood and pellets from madroño Arbutus xalapensis Kunth, tázcate Juniperus deppeana Steud, and encino colorado Quercus sideroxyla Humb. & Bonpl. in two gasifiers (top-lit-up-draft (T-LUD) and electricity generation wood camp stove (EGWCS)) in order to determine the reduction of footprint carbon. In accordance with conventional methodologies, we determined the extracts and chemical components (lignin, cellulose, holocellulose), and the immediate analyses were carried out (volatile materials, fixed carbon, ash content and microanalysis of said ash), as well as the evaluation of emission factors (total suspended particulate matter (PM2.5), CO, CO2, CH4, black carbon (BC), elemental carbon (EC), and organic carbon (OC)). The results were statistically analyzed to compare each variable among species and gasifiers. The raw material analyzed showed how the pH ranged from 5.01 to 5.57, and the ash content ranged between 0.39 and 0.53%. The content values of Cu, Zn, Fe, Mg, and Ca ranged from 0.08 to 0.22, 0.18 to 0.19, 0.38 to 0.84, 1.75 to 1.90, and 3.62 to 3.74 mg kg−1, respectively. The extractive ranges from cyclohexane were 2.48–4.79%, acetone 2.42–4.08%, methanol 3.17–7.99%, and hot water 2.12–4.83%. The range of lignin was 18.08–28.60%. The cellulose content ranged from 43.30 to 53.90%, and holocellulose from 53.50 to 64.02%. The volatile material range was 81.2–87.42%, while fixed carbon was 11.30–17.48%; the higher heating value (HHV) of raw material and pellets presented the ranges 17.68–20.21 and 19.72–21.81 MJ kg−1, respectively. Thermal efficiency showed statistically significant differences (p Arbutus xalapensis being the species with the highest energy yield. The use of improved combustion devices, as well as that of selected raw material species, can reduce the impact of global warming by up to 33% on a cooking task compared to the three-stone burner

Plant Power:Opportunities and challenges for meeting sustainable energy needs from the plant and fungal kingdoms

Societal Impact Statement Bioenergy is a major component of the global transition to renewable energy technologies. The plant and fungal kingdoms offer great potential but remain mostly untapped. Their increased use could contribute to the renewable energy transition and addressing the United Nations Sustainable Development Goal 7 “Ensure access to affordable, reliable, sustainable and modern energy for all.” Current research focuses on species cultivated at scale in temperate regions, overlooking the wealth of potential new sources of small‐scale energy where they are most urgently needed. A shift towards diversified, accessible bioenergy technologies will help to mitigate and adapt to the threats of climate change, decrease energy poverty, improve human health by reducing indoor pollution, increase energy resilience of communities, and decrease greenhouse gas emissions from fossil fuels. Summary Bioenergy derived from plants and fungi is a major component of the global transition to renewable energy technologies. There is rich untapped diversity in the plant and fungal kingdoms that offers potential to contribute to the shift away from fossil fuels and to address the United Nations Sustainable Development Goal 7 (SDG7) “Ensure access to affordable, reliable, sustainable and modern energy for all.” Energy poverty—the lack of access to modern energy services—is most acute in the Global South where biodiversity is greatest and least investigated. Our systematic review of the literature over the last 5 years (2015–2020) indicates that research efforts have targeted a very small number of plant species cultivated at scale, mostly in temperate regions. The wealth of potential new sources of bioenergy in biodiverse regions, where the implementation of SDG7 is most urgently needed, has been largely overlooked. We recommend next steps for bioenergy stakeholders—research, industry, and government—to seize opportunities for innovation to alleviate energy poverty while protecting biodiversity. Small‐scale energy production using native plant species in bioenergy landscapes overcomes many pitfalls associated with bioenergy crop monocultures, such as biodiversity loss and conflict with food production. Targeted trait‐based screening of plant species and biological screening of fungi are required to characterize the potential of this resource. The benefits of diversified, accessible bioenergy go beyond the immediate urgency of energy poverty as more diverse agricultural landscapes are more resilient, store more carbon, and could also reduce the drivers of the climate and environmental emergencies

Implementation Science to Accelerate Clean Cooking for Public Health

Clean cooking has emerged as a major concern for global health and development because of the enormous burden of disease caused by traditional cookstoves and fires. The World Health Organization has developed new indoor air quality guidelines that few homes will be able to achieve without replacing traditional methods with modern clean cooking technologies, including fuels and stoves. However, decades of experience with improved stove programs indicate that the challenge of modernizing cooking in impoverished communities includes a complex, multi-sectoral set of problems that require implementation research. The National Institutes of Health, in partnership with several government agencies and the Global Alliance for Clean Cookstoves, has launched the Clean Cooking Implementation Science Network that aims to address this issue. In this article, our focus is on building a knowledge base to accelerate scale-up and sustained use of the cleanest technologies in low- and middle-income countries. Implementation science provides a variety of analytical and planning tools to enhance effectiveness of clinical and public health interventions. These tools are being integrated with a growing body of knowledge and new research projects to yield new methods, consensus tools, and an evidence base to accelerate improvements in health promised by the renewed agenda of clean cooking.Fil: Rosenthal, Joshua. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Balakrishnan, Kalpana. Sri Ramachandra University; IndiaFil: Bruce, Nigel. University of Liverpool; Reino UnidoFil: Chambers, David. National Institutes of Health. National Cancer Institute; Estados UnidosFil: Graham, Jay. The George Washington University; Estados UnidosFil: Jack, Darby. Columbia University; Estados UnidosFil: Kline, Lydia. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Masera, Omar Raul. Universidad Nacional Autónoma de México; MéxicoFil: Mehta, Sumi. Global Alliance for Clean Cookstoves; Estados UnidosFil: Mercado, Ilse Ruiz. Universidad Nacional Autónoma de México; MéxicoFil: Neta, Gila. National Institutes of Health. National Cancer Institute; Estados UnidosFil: Pattanayak, Subhrendu. University of Duke; Estados UnidosFil: Puzzolo, Elisa. Global LPG Partnership; Estados UnidosFil: Petach, Helen. U.S. Agency for International Development; Estados UnidosFil: Punturieri, Antonello. National Heart, Lung, and Blood Institute; Estados UnidosFil: Rubinstein, Adolfo Luis. Instituto de Efectividad Clínica y Sanitaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sage, Michael. Centers for Disease Control and Prevention; Estados UnidosFil: Sturke, Rachel. National Institutes Of Health. Fogarty International Center; Estados UnidosFil: Shankar, Anita. University Johns Hopkins; Estados UnidosFil: Sherr, Kenny. University of Washington; Estados UnidosFil: Smith, Kirk. University of California at Berkeley; Estados UnidosFil: Yadama, Gautam. Washington University in St. Louis; Estados Unido