Libro: Las Ciencias Políticas y Sociales ante Contingencias de Amplio Impacto. Incógnitas y Propuestas

Ciencia Política, Administración Pública, Política y Gobierno, y Políticas Públicas. Licencia Creative Commons License 3.0 Reconocimiento-No Comercial-Sin Obras Derivadas. Usted es libre de copiar, distribuir y comunicar públicamente la obra bajo las condiciones siguientes: Reconocimiento - Debe reconocer los créditos de la obra de la manera especificada por el autor o el licenciador (pero no de una manera que sugiera que tiene su apoyo o apoyan el uso que hace de su obra). No comercial - No puede utilizar esta obra para fines comerciales. Sin obras derivadas - No se puede alterar, transformar o generar una obra derivada a partir de esta obra.Se analizan desde una perspectiva internacional a interdisciplinaria las vertientes, problemas, incógnitas y propuestas ante una nueva realidad o normalidad, resultado y consecuencia de la pandemia que se vive de manera contemporánea, de tal manera que la problematización abordada realimente propuestas, acciones y rutas adecuadas y satisfactorias que permitan la construcción de futuros promisorios.Academia Internacional de Ciencias Político-Administrativas y Estudios de Futuro, A.C. (IAPAS por sus siglas en inglés)

Impact of Calcium-Silicon nanoparticles on flower quality and biochemical characteristics of Lilium under salt stress

Lilium plants are one of the most important and widely distributed ornamental crops in the world. However, these plants are also susceptible to salinity, an environmental factor that is one of the main ones worldwide. Salinity negatively affects the development and productivity of plants, in addition to the fact that it can affect the quality of flowers in ornamental crops. The use of nanotechnology can be a useful tool to counteract the negative effects of salinity, since the application of nanoparticles can function as a biostimulant and induce positive responses against different types of abiotic stress. In the present study, the foliar application of two types and concentrations of calcium-silicon nanoparticles (Ca-Si NPs) (500 and 750 mg L−1) in lilium plants grown with or without stress and under saline stress (30 mM NaCl) was evaluated. The differences between both nanoparticles were the size and content of inorganic residues, where CaSi-1 had a size of 23.29 nm and a content of inorganic residues of 62.0 %, while CaSi-2 had a size of 15.29 nm and a content of inorganic residues of 87.0 %. The results showed that salinity affected the quality of the flowers, as well as the biochemical parameters of the plants. In contrast, the application of Ca-Si NPs induced positive effects on flower quality, improved flower size and fresh biomass. Under salt stress conditions, the application of Ca-Si NPs in lilium improved the biochemical parameters, increased the content of chlorophylls (up to 38.1 %), vitamin C (9.4 %), and antioxidant capacity (19.2-23.8 %) in the leaves. Regarding the stress indicators in the leaves, the hydrogen peroxide (H2O2) was not affected by salinity or by the Ca-Si NPs, while the malondialdehyde (MDA) increased by the application of the NPs, however, under saline stress there were no differences. In lilium flowers without salt stress, both H2O2 and MDA increased by the application of Ca-Si NPs, while under salt stress only MDA increased. The use of Ca-Si NPs can be an alternative to counteract the harmful effects of salinity stress in plants

Seed Priming with Carbon Nanomaterials Improves the Bioactive Compounds of Tomato Plants under Saline Stress

The consumption of food with a high content of bioactive compounds is correlated with the prevention of chronic degenerative diseases. Tomato is a food with exceptional nutraceutical value; however, saline stress severely affects the yield, the quality of fruits, and the agricultural productivity of this crop. Recent studies have shown that seed priming can mitigate or alleviate the negative effects caused by this type of stress. However, the use of carbon nanomaterials (CNMs) in this technique has not been tested for this purpose. In the present study, the effects of tomato seed priming with carbon nanotubes (CNTs) and graphene (GP) (50, 250, and 500 mg L−1) and two controls (not sonicated and sonicated) were evaluated based on the content of photosynthetic pigments in the leaves; the physicochemical parameters of the fruits; and the presence of enzymatic and non-enzymatic antioxidant compounds, carotenoids, and stress biomarkers such as hydrogen peroxide (H2O2) and malondialdehyde (MDA) in the leaves and fruits of tomato plants without saline stress and with saline stress (50 mM NaCl). The results show that saline stress in combination with CNTs and GP increased the content of chlorophylls (9.1–21.7%), ascorbic acid (19.5%), glutathione (≈13%), proteins (9.9–11.9%), and phenols (14.2%) on the leaves. The addition of CNTs and GP increased the activity of enzymes (CAT, APX, GPX, and PAL). Likewise, there was also a slight increase in the content of H2O2 (by 20.5%) and MDA (3.7%) in the leaves. Salinity affected the quality of tomato fruits. The physico-chemical parameters and bioactive compounds in both the stressed and non-stressed tomato plants were modified with the addition of CNTs and GP. Higher contents of total soluble solids (25.9%), phenols (up to 144.85%), flavonoids (up to 37.63%), ascorbic acid (≈28%), and lycopene (12.4–36.2%) were observed. The addition of carbon nanomaterials by seed priming in tomato plants subjected to saline stress modifies the content of bioactive compounds in tomato fruits and improves the antioxidant defense system, suggesting possible protection of the plant from the negative impacts of stress by salinity. However, analysis of the mechanism of action of CNMs through seed priming, in greater depth is suggested, perhaps with the use of omics sciences

Seed Priming with Carbon Nanomaterials to Modify the Germination, Growth, and Antioxidant Status of Tomato Seedlings

The objective of this work was to determine the responses of tomato seed priming with CNMs (carbon nanomaterials), evaluating the changes in germination and biochemical compounds as well as the effect on the growth of tomato seedlings. Five concentrations of CNMs (10, 100, 250, 500, and 1000 mg L−1) were evaluated, as well as an absolute control and a sonicated control. The results showed that seed priming with CNMs did not affect the germination rate of the tomato seeds; however, it negatively affected the vigor variables, such as the root length (up to 39.2%) and hypocotyl biomass (up to 33%). In contrast, the root biomass was increased by the application of both carbon nanotubes and graphene up to 127% in the best case. Seed priming with carbon nanotubes (1000 mg L−1) decreased the plant height (29%), stem diameter (20%), fresh shoot biomass (63%), fresh root biomass (63%), and dry shoot biomass (71%). Seed priming with graphene increased the content of chlorophylls (up to 111%), vitamin C (up to 78%), β-carotene (up to 11 fold), phenols (up to 85%), and flavonoids (up to 45%), as well as the H2O2 content (up to 215%). Carbon nanotubes (CNTs) increased the enzymatic activity (phenylalanine ammonia lyase (PAL), ascorbate peroxidase (APX), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT). In addition, seed priming with high concentrations of CNMs showed negative effects. Seed priming with carbon nanomaterials can potentially improve the development of the tomato crop; therefore, this technique can be used to induce biostimulation and provides an easy way to apply carbon nanomaterials

Nanostructured Copper Selenide Coatings for Antifouling Applications

The accumulation of microorganisms, plants, algae, or small animals on wet surfaces that have a mechanical function causes biofouling, which can result in structural or other functional deficiencies. The maritime shipping industry must constantly manage biofouling to optimize operational performance, which is a common and long-lasting problem. It can occur on any metal structure in contact with or submerged in ocean water, which represents additional costs in terms of repairs and maintenance. This study is focused on the production of antifouling coatings, made with nanoparticles of copper selenide (CuSe NPs) modified with gum arabic, within a water-base acrylic polymeric matrix. During the curing of the acrylic resin, the CuSe NPs remain embedded in the resin, but this does not prevent the release of ions. The coatings released copper and selenium ions for up to 80 days, and selenium was the element that was released the most. The adhesion of film coatings to metallic substrates showed good adhesion, scale 5B (ASTM D3359 standard). Antimicrobial activity tests show that the coatings have an inhibitory effect on Escherichia coli and Candida albicans. The effect is more noticeable when the coating is detached from the substrate and placed on a growing medium, compared to the coating on a substrate. Scanning electron microscopy (SEM) observations show that nanostructured CuSe coatings are made up of rod-shaped and spherical particles with an average particle size of 101.6 nm and 50 nm, respectively. The energy dispersive X-ray spectroscopy (EDS) studies showed that the ratio of selenium nanoparticles is greater than that of copper and that their distribution is homogeneous

Children living with HIV in Europe: do migrants have worse treatment outcomes?

International audienceTo assess the effect of migrant status on treatment outcomes among children living with HIV in Europe