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

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

Understanding the balance and integration of volume and synaptic transmission. Relevance for psychiatry

The major difference of synaptic transmission vs volume transmission (VT) is about the channels which are private in synaptic transmission (axons and terminals) but diffuse in VT represented by the channel plexus of the extracellular space and the CSF. There exist different forms of VT: extrasynatic, long distance, CSF and roamer type VT, the last one mediated via microvesicles (extracellular vesicles). Interleukin-1b (IL-1b) may produce inflammation and sickness behavior via long distance and CSF VT. The balance and integration of VT and synaptic transmission through receptor–receptor interactions in heteroreceptor complexes appears crucial for CNS communication and of high relevance for psychiatric diseases like schizophrenia, depression, cocaine addiction and anxiety. The allosteric receptor–receptor mechanism causes a marked rise of the repertoire of GPCR recognition, pharmacology, trafficking and signaling of the participating receptor protomers. We have introduced the moonlighting concept into the GPCR heteromer field, since GPCR protomers can change their function through the allosteric receptor–receptor interactions. This is achieved through changes in recognition, G protein selectivity, and signaling via other proteins involving, e.g., a switch from G proteins to b-arrestin through conformationa

Understanding the balance and integration of volume and synaptic transmission. Relevance for psychiatry

The major difference of synaptic transmission vs volume transmission (VT) is about the channels which are private in synaptic transmission (axons and terminals) but diffuse in VT represented by the channel plexus of the extracellular space and the CSF. There exist different forms of VT: extrasynatic, long distance, CSF and roamer type VT, the last one mediated via microvesicles (extracellular vesicles). Interleukin-1b (IL-1b) may produce inflammation and sickness behavior via long distance and CSF VT. The balance and integration of VT and synaptic transmission through receptor\u2013receptor interactions in heteroreceptor complexes appears crucial for CNS communication and of high relevance for psychiatric diseases like schizophrenia, depression, cocaine addiction and anxiety. The allosteric receptor\u2013receptor mechanism causes a marked rise of the repertoire of GPCR recognition, pharmacology, trafficking and signaling of the participating receptor protomers. We have introduced the moonlighting concept into the GPCR heteromer field, since GPCR protomers can change their function through the allosteric receptor\u2013receptor interactions. This is achieved through changes in recognition, G protein selectivity, and signaling via other proteins involving, e.g., a switch from G proteins to b-arrestin through conformational changes in single or several strands of amino acids. It is of substantial interest to understand the role of altered receptor\u2013receptor interactions as a mechanism for how neuroinflammatory processes can contribute to mental dysfunctions. It is hypothesized that chemokine and cytokine receptors may directly form heteroreceptor complexes with neuronal receptors known to be dysfunctional in schizophrenia and targets for antipsychotic drugs. Based on the current bioinformatic analysis performed we can postulate that chemokine receptor CXCR4 may directly interact with GABAB2 and NR2A subunits of the NMDAR, chemokine receptor CCR2 with NMDAR, GABAB1 subunit and GABAAR and cytokine receptor IL1R2 with GABAB1 subunit and NMDAR, all known to be involved in schizophrenia. Through the allosteric receptor\u2013receptor interactions in such pathological heteroreceptor complexes the neuronal NMDA, GABAA and ABAB protomers may change their function (moonlighting) in neuronal networks of the brain. This process in neuroinflammation can contribute to positive, negative and/or cognitive symptoms of schizophrenia in line with the mild encephalitis hypothesis of schizophrenia. Neuroinflammation in schizophrenia may also disturb the integrative process of synaptic and volume transmission signals in glutamate synapses by altering kynurenines in the mammalian brain