Tools for numerical simulation of electrical coronas in aircraft. Research on artificial electrical charging of aircraft and ion seeding

When aircraft go through a high electric field zone, sometimes can trigger lightning, that when strike the aircraft produces damage on the structure or indirect damage on the communications and electronics of the aircraft, due to the high current and electric field of the lightning. Because of the introduction of composite materials on the structure that are bad electric conductors and the use of more electronics on the control and communications system of the aircraft, the danger of severe damages on the aircraft increases. This danger originates the necessity for the development of lightning protection systems for aircraft. The Lightning Research Group (UPC) and the Aeroastro (MIT) are studying and developing a system to electrically charge the aircraft using the corona effect produced on an isolated electrode near the trailing edge of the airfoil. Charging the aircraft in the same polarity as the cloud delays the discharge of the lightning, in consequence protecting it. This system also has other potential applications, as sending ions from the electrode to the atmosphere with the goal of charge it or discharge it, or discharge an aircraft that has been naturally charged during the flight to avoid undesired discharges during the landing. To comprehend better this phenomenon it is important to study it and generate models to simulate it. So in this work, a numerical method has been developed to recreate the corona effect on the electrode, the ions drift velocity around the airfoil, and how the wing-electrode system charges over time. The results obtained are that corona effects appear in the region near the electrode and the size of this area is a function of the potential applied, the altitude, and the charge of the wing. Also, the positive ions are repelled by the electrode and attracted by the wing, but some of them are pulled away by the wind, meanwhile, the negative ions and electrons are attracted by the electrode charging the system negatively. This work concludes that this model is not representative for simulating all the transitory part of charging the wing, mainly because of the computational cost that it has to do it with the necessary precision. But is a good advance of the modeling of the corona effect and with better optimization and more computational power can be usefu

Propagación de luz en guías de onda dieléctricas

Este trabajo consiste en la modelización de la propagación de luz visible en diversos tipos de guías de onda ópticas. El objetivo fundamental es aprender a utilizar el programa de software COMSOL Multiphysics, basado en el método de los elementos finitos, que es un programa muy potente que permite resolver las ecuaciones de Maxwell en sistemas de diferente complejidad. En primer lugar, se utilizará un programa de simulación de acceso abierto que permite simular sistemas multicapa homogéneos, tales como guías de onda planares, y cuyos resultados pueden compararse con soluciones analíticas. A continuación, se utilizará el programa COMSOL Multiphysics, en primer lugar, para reproducir los resultados de estructuras sencillas obtenidos anteriormente; y en segundo lugar, y en la medida de lo posible, para abordar sistemas más complejos, tales como los consistentes en guías de onda con una capa superior que tiene una modulación periódica de su espesor (una red de difracción de relieve). Este tipo de estructura es la que tienen los láseres con realimentación distribuida, que son utilizados en una gran diversidad de aplicaciones. Siguiendo este proceso, se han estudiado diferentes sistemas de guías de onda, variando diversos parámetros (espesores, índices de refracción y longitud de onda) para, de esta forma, estudiar los parámetros necesarios para una propagación óptima de la luz en una guía de ondas. Para contrastar la información, se han comparado los resultados de los dos softwares verificando su similitud y confirmando el correcto uso de ambos programas

Investigation of the Effects of Metallic Nanoparticles on Fertility Outcomes and Endocrine Modification of the Hypothalamic-Pituitary-Gonadal Axis

first_pagesettingsOrder Article Reprints Open AccessArticle Investigation of the Effects of Metallic Nanoparticles on Fertility Outcomes and Endocrine Modification of the Hypothalamic-Pituitary-Gonadal Axis by Miguel A. SogorbORCID,Héctor CandelaORCID,Jorge Estévez andEugenio Vilanova *ORCID Instituto de Bioingeniería, Universidad Miguel Hernández de Elche, Avenida de la Universidad s/n, 03202 Elche, Spain * Author to whom correspondence should be addressed. Int. J. Mol. Sci. 2023, 24(14), 11687; https://doi.org/10.3390/ijms241411687 Submission received: 30 May 2023 / Revised: 11 July 2023 / Accepted: 13 July 2023 / Published: 20 July 2023 (This article belongs to the Special Issue Molecular Mechanisms of Reproductive and Developmental Toxicology) Downloadkeyboard_arrow_down Browse Figures Review Reports Versions Notes Abstract Nanotechnology is a very disruptive twenty-first-century revolution that will allow social and economic welfare to increase although it also involves a significant human exposure to nanoparticles. The aim of the present study was to contribute to the elucidation on whether metallic nanoparticles have a potential to induce fertility impairments. Regulatory studies that observed official OECD guidelines 415, 416 and 422 have failed to detect any fertility alterations caused by nanoparticle exposure. However, the scientific literature provides evidence that some nanoparticles may cause gonad impairments although the actual impact on fertility remains uncertain. This aim of the present study is to revisit the previously published RNAseq studies by analyzing the effects of several nanoparticles on the transcriptome of T98G human glioblastoma cells given that glial cells are known to play a pivotal role in the regulation of gonadotropin releasing hormone neurons. We found evidence that nanoparticles impair the gonadotropin releasing hormone receptor pathway and several related biological process like, among others, the cellular response to follicular stimulating hormone, cellular response to gonadotropin stimulus, cellular response to hormone stimulus, response to steroid hormone, ovulation cycle and response to estradiol. We propose that nanoparticles interfere with the ability of glial cells to regulate gonadotropin-releasing hormone neurons and, subsequently, the hypothalamic-pituitary-gonadal axis, potentially leading to fertility impairments. To our knowledge, this is the first proposal of a mode of action based on endocrine disruption for explaining the possible effects of nanoparticles on fertility. Whether these finding can be extended to other types of nanoparticles requires further investigation

Titanium Dioxide, but Not Zinc Oxide, Nanoparticles Cause Severe Transcriptomic Alterations in T98G Human Glioblastoma Cells

Titanium dioxide and zinc oxide are two of the most widely used nanomaterials. We assessed the effects of noncytotoxic doses of both nanomaterials on T98G human glioblastoma cells by omic approaches. Surprisingly, no effects on the transcriptome of T98G cells was detected after exposure to 5 g/mL of zinc oxide nanoparticles during 72 h. Conversely, the transcriptome of the cells exposed to 20 g/mL of titanium dioxide nanoparticles during 72 h revealed alterations in lots of biological processes and molecular pathways. Alterations to the transcriptome suggests that exposure to titanium dioxide nanoparticles might, potentially, compromise the integrity of the blood brain barrier integrity and cause neuroinflammation. The latter issue was further confirmed phenotypically with a proteomic analysis and by recording the release of interleukin 8. Titanium dioxide also caused autophagy, which was demonstrated through the increase in the expression of the autophagy-related 3 and microtubule associated protein 1 light chain 3 alpha genes. The proteomic analysis revealed that titanium dioxide nanoparticles might have anticancerigen properties by downregulating genes involved in the detoxication of anthracyclines. A risk assessment resulting from titanium dioxide exposure, focusing on the central nervous system as a potential target of toxicity, is necessary

A Transcriptomic Analysis of T98G Human Glioblastoma Cells after Exposure to Cadmium-Selenium Quantum Dots Mainly Reveals Alterations in Neuroinflammation Processes and Hypothalamus Regulation

Quantum dots are nanoparticles with very promising biomedical applications. However, before these applications can be authorized, a complete toxicological assessment of quantum dots toxicity is needed. This work studied the effects of cadmium-selenium quantum dots on the tran scriptome of T98G human glioblastoma cells. It was found that 72-h exposure to 40 µg/mL (a dose that reduces cell viability by less than 10%) alters the transcriptome of these cells in biological pro cesses and molecular pathways, which address mainly neuroinflammation and hormonal control of hypothalamus via the gonadotropin-releasing hormone receptor. The biological significance of neuroinflammation alterations is still to be determined because, unlike studies performed with other nanomaterials, the expression of the genes encoding pro-inflammatory interleukins is down-regulated rather than up-regulated. The hormonal control alterations of the hypothalamus pose a new concern about a potential adverse effect of quantum dots on fertility. In any case, more studies are needed to clarify the biological relevance of these findings, and especially to assess the real risk of toxicity derived from quantum dots exposure appearing in physiologically relevant scenarios

From Classical to Modern Computational Approaches to Identify Key Genetic Regulatory Components in Plant Biology

The selection of plant genotypes with improved productivity and tolerance to environmental constraints has always been a major concern in plant breeding. Classical approaches based on the generation of variability and selection of better phenotypes from large variant collections have improved their efficacy and processivity due to the implementation of molecular biology techniques, particularly genomics, Next Generation Sequencing and other omics such as proteomics and metabolomics. In this regard, the identification of interesting variants before they develop the phenotype trait of interest with molecular markers has advanced the breeding process of new varieties. Moreover, the correlation of phenotype or biochemical traits with gene expression or protein abundance has boosted the identification of potential new regulators of the traits of interest, using a relatively low number of variants. These important breakthrough technologies, built on top of classical approaches, will be improved in the future by including the spatial variable, allowing the identification of gene(s) involved in key processes at the tissue and cell levels

Sedimentary evidence of historical and prehistorical earthquakes along the Venta de Bravo Fault System, Acambay Graben (Central Mexico)

The Venta de Bravo normal fault is one of the longest structures in the intra-arc fault system of the Trans-Mexican Volcanic Belt. It defines, together with the Pastores Fault, the 80 km long southern margin of the Acambay Graben. We focus on the westernmost segment of the Venta de Bravo Fault and provide new paleoseismological information, evaluate its earthquake history, and assess the related seismic hazard. We analyzed five trenches, distributed at three different sites, in which Holocene surface faulting offsets interbedded volcanoclastic, fluvio-lacustrine and colluvial deposits. Despite the lack of known historical destructive earthquakes along this fault, we found evidence of at least eight earthquakes during the late Quaternary. Our results indicate that this is one of the major seismic sources of the Acambay Graben, capable of producing by itself earthquakes with magnitudes (MW) up to 6.9, with a slip rate of 0.22-0.24 mm yr− 1 and a recurrence interval between 1940 and 2390 years. In addition, a possible multi-fault rupture of the Venta de Bravo Fault together with other faults of the Acambay Graben could result in a MW > 7 earthquake. These new slip rates, earthquake recurrence rates, and estimation of slips per event help advance our understanding of the seismic hazard posed by the Venta de Bravo Fault and provide new parameters for further hazard assessment

Turning Garlic into a Modern Crop: State of the Art and Perspectives

Garlic is cultivated worldwide for the value of its bulbs, but its cultivation is challenged by the infertility of commercial cultivars and the accumulation of pathogens over time, which occurs as a consequence of vegetative (clonal) propagation. In this review, we summarize the state of the art of garlic genetics and genomics, highlighting recent developments that will lead to its development as a modern crop, including the restoration of sexual reproduction in some garlic strains. The set of tools available to the breeder currently includes a chromosome-scale assembly of the garlic genome and multiple transcriptome assemblies that are furthering our understanding of the molecular processes underlying important traits like the infertility, the induction of flowering and bulbing, the organoleptic properties and resistance to various pathogens

Evidence of recent ruptures in the central faults of the Acambay Graben (central Mexico)

The Acambay Graben, within the central part of the Trans-Mexican Volcanic Belt, is one of the major sources of continental earthquakes in Mexico. To date, the activity and paleoseismological history of the axial faults of the graben are not well constrained. We provide morphological, structural and sedimentological evidence of the seismogenic nature of two of the axial structures, the Temascalcingo and the Tepuxtepec fault systems. Faults consist of multiple parallel scarps with en echelon and horse-splay patterns. Fault systems extend for 60 km and displace Quaternary to Upper Miocene volcanic edifices and volcano-sedimentary materials. Surface lengths of individual fault traces range between 3 and 25 km, and observed throws reach a minimum of 150-200 m. The long-term and short-term slip rate of the Temascalcingo fault system in the studied section presents similar values, ranging from 0.06 ± 0.02 (minimum long term) to 0.12 ± 0.02 mm y−1 (maximum value of average short-term). Only the long-term slip rate of the Tepuxtepec system could be constrained in 0.01-0.02 mm/y, being a minimum estimate. The Holocene fault rupture history at two sites provided evidence of six ruptures since 12,500-11,195 BCE, among which three ruptures should have occurred between 11,847 ± 652 BCE and 11,425 ± 465 BCE Variable single event displacements (SEDs, between 6 and 77) are interpreted as the result of fault interdependences and/or the interaction with the latest volcanic activity. Also, small displacements triggered by activity on other faults probably contributed to slip variability, i.e., faults display primary and secondary behavior

Identification of ABA-Mediated Genetic and Metabolic Responses to Soil Flooding in Tomato (Solanum lycopersicum L. Mill)

[EN] Soil flooding is a compound abiotic stress that alters soil properties and limits atmospheric gas diffusion (O-2 and CO2) to the roots. The involvement of abscisic acid (ABA) in the regulation of soil flooding-specific genetic and metabolic responses has been scarcely studied despite its key importance as regulator in other abiotic stress conditions. To attain this objective, wild type and ABA-deficient tomatoes were subjected to short-term (24 h) soil waterlogging. After this period, gas exchange parameters were reduced in the wild type but not in ABA-deficient plants that always had higher E and g(s). Transcript and metabolite alterations were more intense in waterlogged tissues, with genotype-specific variations. Waterlogging reduced the ABA levels in the roots while inducing PYR/PYL/RCAR ABA receptors and ABA-dependent transcription factor transcripts, of which induction was less pronounced in the ABA-deficient genotype. Ethylene/O-2-dependent genetic responses (ERFVIIs, plant anoxia survival responses, and genes involved in the N-degron pathway) were induced in hypoxic tissues independently of the genotype. Interestingly, genes encoding a nitrate reductase and a phytoglobin involved in NO biosynthesis and scavenging and ERFVII stability were induced in waterlogged tissues, but to a lower extent in ABA-deficient tomato. At the metabolic level, flooding-induced accumulation of Ala was enhanced in ABA-deficient lines following a differential accumulation of Glu and Asp in both hypoxic and aerated tissues, supporting their involvement as sources of oxalacetate to feed the tricarboxylic acid cycle in waterlogged tissues and constituting a potential advantage upon long periods of soil waterlogging. The promoter analysis of upregulated genes indicated that the production of oxalacetate from Asp via Asp oxidase, energy processes such as acetyl-CoA, ATP, and starch biosynthesis, and the lignification process were likely subjected to ABA regulation. Taken together, these data indicate that ABA depletion in waterlogged tissues acts as a positive signal, inducing several specific genetic and metabolic responses to soil flooding.This work was supported by the Spanish Ministerio de Economia y Competitividad, Universitat Jaume I and Generalitat Valenciana/Fondo Europeo de Desarrollo Regional (FEDER), co-funded through grant nos. AGL2016-76574-R, UJI-B201623, UJI-B2016-24, IDIFEDER/2018/010, and UJI-B2019-24 to AG-C, VA, and MG-G, respectively. CD was supported by UJI PICD program. MG-G and JM were supported by Ramon y Cajal contracts from Spanish Ministerio de Economia y Competitividad (RYC-2016-19325 and RYC-201723645, respectively). JR was supported by a Juan de la CiervaFormacion contract from the Spanish Ministerio de Economia y Competitividad (FJCI-2016-28601).De Ollas, C.; González-Guzmán, M.; Pitarch, Z.; Matus, JT.; Candela, H.; Rambla Nebot, JL.; Granell Richart, A.... (2021). Identification of ABA-Mediated Genetic and Metabolic Responses to Soil Flooding in Tomato (Solanum lycopersicum L. Mill). Frontiers in Plant Science. 12:1-20. https://doi.org/10.3389/fpls.2021.613059S1201