Exergy efficiency assessment of corn-based ethanol production : a case study in the Pampas region (Argentina)

La transformación de los sistemas naturales en sistemas productivos altera no sólo su estructura sino también su funcionalidad. La necesidad de evaluar y monitorear esos cambios funcionales ha llevado al desarrollo y la aplicación de un gran número de indicadores del impacto de las actividades humanas sobre los ecosistemas. En este trabajo se presenta un marco teórico para el estudio del deterioro de los ecosistemas agrícolas a través del análisis de los flujos de energía. Se presentan los fundamentos de la evaluación del funcionamiento de los agroecosistemas a través del uso de la energía útil o exergía, y se ilustra la metodología de cálculo en un sistema agrícola de la Región Pampeana destinado a la producción de etanol sobre la base de grano de maíz. Los resultados indican que si bien el impacto potencial en términos de extracción de recursos (bajo la forma de exergía consumida) es mayor en la fase industrial, las ineficiencias en la fase agrícola son mucho más marcadas. En cuanto al ciclado interno de exergía, los resultados de este trabajo indican que 41% de la exergía utilizada para obtener 1 MJ de exergía proviene de fuentes no renovables, y se eleva a 71% si se toma en cuenta el aporte neto de exergía del combustible, después de descontarle los costos exergéticos acumulados durante los procesos de elaboración. Estos resultados indican que el sistema analizado de producción de etanol sobre la base de maíz cumple de manera parcial las condiciones deseables de baja extracción de recursos del ambiente y alta renovabilidad de la producción.Natural ecosystems transformation in agroecosystems not only alters its structure but also its functionality. The need to evaluate and monitor these functional changes has led to the development and implementation of a large number of indicators of human impact due to agricultural activities. This paper develops a theoretical framework for the assessment of agroecosystems through the analysis of energy flows. In particular, the approach is based on the use of energy or useful exergy. Also, the calculation methodology is applied to a corn-based ethanol farming system located in the Pampa Region. Results indicate that although the potential impact in terms of resource extraction from the environment, in the form of exergy consumed, is highest in the industrial stage, the inefficiencies in the agricultural phase are much more pronounced. As for the internal cycling of exergy, the results of this study indicate that 41% of the exergy used to get 1 MJ of exergy comes from non-renewable sources, rising to 71% when you take into account the contribution of net exergy fuel. These results indicate that the crop-based system analyzed for ethanol production partially meets the desirable conditions of low resource extraction from the environment and high renewability of production

A new methodological approach based on conceptual and probabilistic networks to assess ecosystem services provision

En los últimos años han surgido varias herramientas para evaluar la provisión de servicios de los ecosistemas (SE) desde un punto de vista ecológico. No obstante, la complejidad de los SE desalienta los intentos de adoptar una única aproximación metodológica. El objetivo de este trabajo consistió en evaluar un nuevo marco de análisis de la provisión de SE, sobre la base de redes conceptuales y redes probabilísticas. Para cumplir con el objetivo se describió el desarrollo de una red conceptual y se representó el conjunto de variables que determinan la provisión de ocho SE de la Región Pampeana. Luego, se parametrizó esa red mediante una metodología probabilística conocida como Redes Bayesianas, para ser, después, aplicada a tres zonas agrícolas pampeanas. Por último, se plantearon ventajas y desventajas de este nuevo marco de análisis mediante una comparación con otras aproximaciones para el estudio de la provisión de SE, desarrolladas en Argentina y en otras partes del mundo, tales como InVEST, RIOS, ARIES y ECOSER. El enfoque aquí presentado puede ser útil para: a) evaluar la sustentabilidad de los agroecosistemas pampeanos desde una dimensión ecológica, o b) asistir a los tomadores de decisión (i.e., productores y asesores agropecuarios) para implementar estrategias sustentables de uso de la tierra.In the last few years, there have been an increasing number of tools to environmentally assess ecosystem services (ES) provision. However, its complexity discourages attemptsto adopt a single methodological approach. Then, the aim of this study was to assess a new framework toanalyze ES provision, based on conceptual and probabilistic networks. First, the new methodological approach was described. This approach consisted of a conceptual network representing those variables that determine eight ES provided by the Pampa region. The conceptual network was parameterized using a probabilistic methodology known as Bayesian networks, and then was applied to three Pampean agroecosystems. Finally,the new analytical framework was compared with other national and international approaches that assess ES provision, such as InVEST, RIOS, ARIES and ECOSER. The approach presented here could be helpful to: a)assess the sustainability of Pampean agroecosystems from an ecological dimension, and/or b) to assist decision makers (i.e., farmers and their advisors) in the implementation of sustainable land use strategies

Desempeño biofísico y económico de sistemas de cultivos extensivos: una aproximación basada en modelos de simulación y algoritmos genéticos

En este trabajo se presenta un framework basado en modelos de simulación de cultivos y algoritmos genéticos para encontrar las combinaciones de variables de manejo (i.e. fertilización, secuencias y estructura de cultivos, y aplicación de fitosanitarios) que optimicen el desempeño biofísico y económico de sistemas de agrícolas extensivos. Además, se proponen valores umbral hipotéticos para las variable biofísicas y económicas a partir del cual se podría generar el colapso del sistema. Se generó una herramienta de diagnóstico que permite medir la distancia entre el desempeño de prácticas reales modales para Pergamino y los óptimos obtenidos mediante la optimización del algoritmo genético. Finalmente, se discuten las limitaciones de este tipo de aproximación y las implicancias para el diseño de sistemas de cultivos extensivos sustentables.Sociedad Argentina de Informática e Investigación Operativ

Decision Support Systems for Weed Management

Editors: Guillermo R. Chantre, José L. González-Andújar.Weed management Decision Support Systems (DSS) are increasingly important computer-based tools for modern agriculture. Nowadays, extensive agriculture has become highly dependent on external inputs and both economic costs, as well the negative environmental impact of agricultural activities, demands knowledge-based technology for the optimization and protection of non-renewable resources. In this context, weed management strategies should aim to maximize economic profit by preserving and enhancing agricultural systems. Although previous contributions focusing on weed biology and weed management provide valuable insight on many aspects of weed species ecology and practical guides for weed control, no attempts have been made to highlight the forthcoming importance of DSS in weed management. This book is a first attempt to integrate 'concepts and practice' providing a novel guide to the state-of-art of DSS and the future prospects which hopefully would be of interest to higher-level students, academics and professionals in related areas

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Historical trends of the ecotoxicological pesticide risk from the main grain crops in Rolling Pampa (Argentina).

We showed the results of the first long-term analysis (1987-2019) of pesticide (herbicides, fungicides and insecticides) impact in the Rolling Pampa, one of the main agricultural areas of Argentina. Using a clear and meaningful tool, based not only on acute toxicity but also on scaling up the results to total sown area, we identified time trends for both pesticide impact and the ecoefficiency of modal pesticide profiles. By the end of the time series, soybean showed a pesticide impact four times greater than maize crop in the studied area. However, the time trend in the subperiod (2012-2019) showed a sustainable pattern of pesticide use in soybean crop, with an improvement in its ecoefficiency. Oppositely, maize showed a relatively constant ecoefficiency value during most of the time series, suggesting a possible path towards an unsustainable cropping system. Findings from this study suggest that some efforts have to be made to improve the pest management decisions towards a more efficient pesticide profiles in maize crop and to keep improving the ecotoxicity pesticide profile in soybean crops because of its large sown area in the studied area

Distributed Optical Fiber Radiation Sensing at CERN

International audienceCERN’s accelerator tunnels are very complex mixed field radiation environments, in which many electronic components and systems are installed. The radiation generated by the circulating beam degrades all electronic equipment and impacts directly its lifetime. In the worst case, it may also cause failures that contribute to increase the machine downtime periods. Consequently, both active and passive dosimetry technologies are used to monitor the radiation levels. These point radiation sensors are installed in thousands of specific locations in the machine tunnels, and the nearby caverns, in order to provide either online or post-irradiation radiation dose measurements. In this contribution, we present a new radiation monitoring technology implemented at CERN called Distributed Optical Fiber Radiation Sensor (DOFRS). The first operational prototype of this system was installed in 2017 in the Proton Synchrotron Booster (PSB), the first and smallest circular accelerator of the injection chain of LHC. The most interesting capability of the DOFRS, with respect to other currently installed dosimetry systems, is to provide one dimensional maps of radiation dose levels all along the sensing Optical Fiber (OF). Such characteristic makes it very well-adapted for radiation detection and dosimetry in large facilities and accelerators. In particular, it allows the online monitoring of the cumulated radiation dose over hundreds of meters with a spatial resolution down to one meter. By combining these measurements with simulation studies, it is also possible to draw conclusions on the radiation dose levels at locations closer to the beam line. Below, we report the results and performances of the DOFRS in the PSB after its first year of operation. The measurements are compared to several point passive dosimeters that were installed in regions of interest in close proximity to the OF sensor. Furthermore, the system under implementation at CERN provide distributed temperature measurement capabilities specifically adapted for radiation environmen

GPCR HETEROMERS AND THEIR ALLOSTERIC RECEPTOR-RECEPTOR INTERACTIONS

The concept of intramembrane receptor-receptor interactions and evidence for their existences was introduced in the beginning of the 1980’s, suggesting the existence of receptor heterodimerization. The discovery of GPCR heteromers and the receptor mosaic (higher order oligomers, more than two) has been related to the parallel development and application of a variety of resonance energy transfer techniques such as bioluminescence (BRET), fluorescence (FRET) and sequential energy transfer (SRET). The assembly of interacting GPCRs, heterodimers and receptor mosaic lead to changes in the agonist recognition, signaling, and trafficking of participating receptors via allosteric mechanisms, sometimes involving the appearance of cooperativity. The receptor interface in the GPCR heteromers is beginning to be characterized and the key role of electrostatic epitope-epitope interactions for the formation of the receptor heteromers will be discussed. Furthermore a "guide-and-clasp" manner of receptor-receptor interactions has been proposed where the "adhesive guides" may be the triplet homologies. These interactions probably represent a general molecular mechanism for receptor-receptor interactions. It is proposed that changes in GPCR function (moonlighting) may develop through the intracellular loops and C-terminii of the GPCR heteromers as a result of dynamic allosteric interactions between different types of G proteins and other receptor interacting proteins in these domains of the receptors. The evidence for the existence of receptor heteromers opens up a new field for a better understanding of neurophysiology and neuropathology. Furthermore, novel therapeutic approaches could be possible based on the use of heteromers as targets for a drug development based on their unique pharmacology