Food hub: Una alternativa para alimentar las ciudades de manera sostenible

La tarea de alimentar las ciudades es un reto al que hoy se enfrentan todos los gobiernos e implica una coordinación de múltiples productores, distribuidores, operadores logísticos y comerciantes de alimentos perecederos. Este artículo pretende analizar los Food hubs en el sistema de distribución urbano de alimentos, de manera crítica y sistemática desde la literatura. Se presenta en primera instancia un estado del arte sobre el concepto de Food hub, luego se presenta una propuesta de tipificación de Food hubs de acuerdo a unos criterios, concentrándose en actores implicados en el proceso de distribución de alimentos, estructura jurídica y sus funciones. También se describen los impactos sociales, económicos y medioambientales que traería consigo la implementación de un Food hub. Finalmente, se presentan las principales oportunidades para la expansión de Food hubs urbanos y se exponen cuatro ejemplos latinoamericanos, relacionándolos con la tipología propuesta. Food hub as an efficient alternative to sustainably feed the cities. The task of feeding cities is a challenge that nowadays all governments face, it involves the coordination of multiple producers, distributors, logistics operators and traders of perishable foods. This paper analyzes the Food hubs concept and its impact on urban development in a critical perception from the literature review. The state of the art on the concept of Food Hub is presented at first instance. Then a classification of different types of Food hub is done by focusing on the actors involved in the food system distribution process, structure and functions. After that, an analysis of the prospects of the implementation of Food hubs is performed, evaluating its economic, social and environmental impacts. Finally, the main opportunities for the deployment of urban Food hubs are presented, and four Latin-American cases are introduced, linked them with the proposed typolog

Nicotianamine Synthase 2 Is Required for Symbiotic Nitrogen Fixation in Medicago truncatula Nodules

Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires relatively large levels of transition metals. These elements are cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vasculature, in a process mediated by a number of metal transporters and small organic molecules that facilitate metal delivery in the plant fluids. Among the later, nicotianamine is one of the most important. Synthesized by nicotianamine synthases (NAS), this molecule forms metal complexes participating in intracellular metal homeostasis and long-distance metal trafficking. Here we characterized the NAS2 gene from model legume Medicago truncatula. MtNAS2 is located in the root vasculature and in all nodule tissues in the infection and fixation zones. Symbiotic nitrogen fixation requires of MtNAS2 function, as indicated by the loss of nitrogenase activity in the insertional mutant nas2-1, phenotype reverted by reintroduction of a wild-type copy of MtNAS2. This would result from the altered iron distribution in nas2-1 nodules shown with X-ray fluorescence. Moreover, iron speciation is also affected in these nodules. These data suggest a role of nicotianamine in iron delivery for symbiotic nitrogen fixation

Desarrollo de copos dulces a base de harina integral de quínoa (chenopodium quínoa willd), libres de gluten

Fil: Cuello, J. R. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: De Lima Argüello, P. B. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Seuchuc, M. L. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Cervilla, N. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Calandri, E. L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Calandri, E. L. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencia y Tecnología de los Alimentos Córdoba; Argentina.Se propuso aquí lograr una formulación que aportara a los copos dulces (CD) mayor valor nutritivo y buena aceptación por parte de los consumidores. Se recurrió a un diseño experimental según el método de Taguchi. Los factores evaluados fueron: fécula de mandioca, harina de arroz, tiempo de cocción y CaCO3. Harina integral de quínoa (HIQ), azúcar y goma xántica se mantuvieron constantes. Como parámetro de salida se recurrió a mediciones de textura de los copos, evaluándose la tortuosidad de las curvas de fuerza de compresión vs tiempo. Tres de los nueve ensayos presentaron las mayores tortuosidades y fuerzas de compresión máxima y correspondieron a las siguientes formulaciones: M3: 40% de fécula de mandioca, 40% de harina integral de quínoa y 8% de CaCO3; M5: 22% de harina de arroz, 22% de fécula de mandioca y 44% de HIQ; M7: 42% harina de arroz, 42% de HIQ y 4% de CaCO3. La composiciónquímica de los copos dulces fue similar a los copos de maíz tradicionales, aunque de mejor calidad proteica debido a HIQ. La aceptabilidad de los CD fue menor al 50%; posiblemente porque presentaron mayores fuerzas de compresión que los copos tradicionales, elaborados con maíz.http://cicytac.cba.gov.ar/es/..%5CedicionesAnt%5C2014%5C7-Trabajos%20completos%20Nutricion%20y%20Salud%20-%20V%20CICyTAC%202014.-.pdfFil: Cuello, J. R. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: De Lima Argüello, P. B. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Seuchuc, M. L. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Cervilla, N. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Calandri, E. L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Ciencia y Tecnología de los Alimentos; Argentina.Fil: Calandri, E. L. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencia y Tecnología de los Alimentos Córdoba; Argentina.Alimentos y Bebida

Experimental implementation of a neural network optical channel equalizer in restricted hardware using pruning and quantization

The deployment of artificial neural networks-based optical channel equalizers on edge-computing devices is critically important for the next generation of optical communication systems. However, this is still a highly challenging problem, mainly due to the computational complexity of the artificial neural networks (NNs) required for the efficient equalization of nonlinear optical channels with large dispersion-induced memory. To implement the NN-based optical channel equalizer in hardware, a substantial complexity reduction is needed, while we have to keep an acceptable performance level of the simplified NN model. In this work, we address the complexity reduction problem by applying pruning and quantization techniques to an NN-based optical channel equalizer. We use an exemplary NN architecture, the multi-layer perceptron (MLP), to mitigate the impairments for 30 GBd 1000 km transmission over a standard single-mode fiber, and demonstrate that it is feasible to reduce the equalizer's memory by up to 87.12%, and its complexity by up to 78.34%, without noticeable performance degradation. In addition to this, we accurately define the computational complexity of a compressed NN-based equalizer in the digital signal processing (DSP) sense. Further, we examine the impact of using hardware with different CPU and GPU features on the power consumption and latency for the compressed equalizer. We also verify the developed technique experimentally, by implementing the reduced NN equalizer on two standard edge-computing hardware units: Raspberry Pi 4 and Nvidia Jetson Nano, which are used to process the data generated via simulating the signal's propagation down the optical-fiber system

Hetero-cycloreversions Mediated by Photoinduced Electron Transfer

[EN] Discovered more than eight decades ago, the Diels-Alder (DA) cycloaddition (CA) remains one of the most versatile tools in synthetic organic chemistry. Hetero-DA processes are powerful methods for the synthesis of densely functionalized six-membered heterocycles, ubiquitous substructures found in natural products and bioactive compounds. These reactions frequently employ azadienes and oxadienes, but only a few groups have reported DA processes with thiadienes. The electron transfer (ET) version of the DA reaction, though less investigated, has emerged as a subject of increasing interest. In the last two decades, researchers have paid closer attention to radical ionic hetero-cycloreversions, mainly in connection with their possible involvement in the repair of pyrimidine(6-4)pyrimidone photolesions in DNA by photolyases. In biological systems, these reactions likely occur through a reductive photosensitization mechanism. In addition, photooxidation can lead to cycloreversion (CR) reactions, and researchers can exploit this strategy for DNA repair therapies. In this Account, we discuss electron-transfer (ET) mediated hetero-CR reactions. We focus on the oxidative and reductive ET splitting of oxetanes, azetidines, and thietanes. Photoinduced electron transfer facilitates the splitting of a variety of four-membered heterocycles. In this context, researchers have commonly examined oxetanes, both experimentally and theoretically. Although a few studies have reported the cycloreversion of azetidines and thietanes carried out under electron transfer conditions, the number of examples remains limited. In general, the cleavage of the ionized four-membered rings appears to occur via a nonconcerted two-step mechanism. The trapping of the intermediate 1,4-radical ions and transient absorption spectroscopy data support this hypothesis, and it explains the observed loss of stereochemistry in the products. In the initial step, either C-C or C-X bond breaking may occur, and the preferred route depends on the substitution pattern of the ring, the type of heteroatom, and various experimental conditions. To better accommodate spin and charge, C-X cleavage happens more frequently, especially in the radical anionic version of the reaction. The addition or withdrawal of a single electron provides a new complementary synthetic strategy to activate hetero-cycloreversions. Despite its potential, this strategy remains largely unexplored. However, it offers a useful method to achieve C=X/olefin metathesis or, upon ring expansion, to construct six-membered heterocyclic rings.Financial support from the Spanish Government (Grants CTQ2010-14882, SEV2012-0267, and JCI-2010-06204) and the Generalitat Valenciana (Prometeo II/2013/005) is gratefully acknowledged.Pérez Ruiz, R.; Jiménez Molero, MC.; Miranda Alonso, MÁ. (2014). Hetero-cycloreversions Mediated by Photoinduced Electron Transfer. Accounts of Chemical Research. 47(4):1359-1368. https://doi.org/10.1021/ar4003224S1359136847

Extensive Sheep and Goat Production: The Role of Novel Technologies towards Sustainability and Animal Welfare

[EN] Sheep and goat extensive production systems are very important in the context of global food security and the use of rangelands that have no alternative agricultural use. In such systems, there are enormous challenges to address. These include, for instance, classical production issues, such as nutrition or reproduction, as well as carbon-efficient systems within the climate-change context. An adequate response to these issues is determinant to economic and environmental sustainability. The answers to such problems need to combine efficiently not only the classical production aspects, but also the increasingly important health, welfare, and environmental aspects in an integrated fashion. The purpose of the study was to review the application of technological developments, in addition to remote-sensing in tandem with other state-of-the-art techniques that could be used within the framework of extensive production systems of sheep and goats and their impact on nutrition, production, and ultimately, the welfare of these species. In addition to precision livestock farming (PLF), these include other relevant technologies, namely omics and other areas of relevance in small-ruminant extensive production: heat stress, colostrum intake, passive immunity, newborn survival, biomarkers of metabolic disease diagnosis, and parasite resistance breeding. This work shows the substantial, dynamic nature of the scientific community to contribute to solutions that make extensive production systems of sheep and goats more sustainable, efficient, and aligned with current concerns with the environment and welfareSIThe CECAV authors acknowledge financial support of the research unit, which was financed by the National Funds from FCT, the Portuguese Foundation for Science and Technology (FCT), project number UIDB/CVT/00772/2020. Financial support from FCT (Fundação para a Ciência e a Tecnologia, Lisboa, Portugal) in the form of infrastructural funding to LEAF (UID/AGR/04129) and PhD grants SFRH/BD/143992/2019 (DM Ribeiro) and 2021.07638.BD (L Sacarrão-Birrento). Author L.E.H.C. acknowledges funding from the Agencia Estatal de Investigación (Spain) (RYC2019- 027064-I/AEI/10.13039/501100011033

Oxphos Promotes Apoptotic Resistance and Cellular Persistence in TH17 Cells in the Periphery and Tumor Microenvironment

T cell proliferation and cytokine production are bioenergetically and biosynthetically costly. The inability to meet these metabolic demands results in altered differentiation, accompanied by impaired effector function, and attrition of the immune response. Interleukin-17-producing CD4 T cells (TH17s) are mediators of host defense, autoimmunity, and antitumor immunity in the setting of adoptive T cell therapy. TH17s are long-lived cells that require mitochondrial oxidative phosphorylation (OXPHOS) for effector function in vivo. Considering that TH17s polarized under standardized culture conditions are predominately glycolytic, little is known about how OXPHOS regulates TH17 processes, such as their ability to persist and thus contribute to protracted immune responses. Here, we modified standardized culture medium and identified a culture system that reliably induces OXPHOS dependence in TH17s. We found that TH17s cultured under OXPHOS conditions metabolically resembled their in vivo counterparts, whereas glycolytic cultures were dissimilar. OXPHOS TH17s exhibited increased mitochondrial fitness, glutamine anaplerosis, and an antiapoptotic phenotype marked by high BCL-XL and low BIM. Limited mitophagy, mediated by mitochondrial fusion regulator OPA-1, was critical to apoptotic resistance in OXPHOS TH17s. By contrast, glycolytic TH17s exhibited more mitophagy and an imbalance in BCL-XL to BIM, thereby priming them for apoptosis. In addition, through adoptive transfer experiments, we demonstrated that OXPHOS protected TH17s from apoptosis while enhancing their persistence in the periphery and tumor microenvironment in a murine model of melanoma. Together, our work demonstrates how metabolism regulates TH17 cell fate and highlights the potential for therapies that target OXPHOS in TH17-driven diseases