Temporal and spatial association between microwaves and type III bursts in the upper corona

One of the most important tasks in solar physics is the study of particles and energy transfer from the lower corona to the outer layers of the solar atmosphere. The most sensitive methods for detecting fluxes of non-thermal electrons in the solar atmosphere is observing their radio emission using modern large radioheliographs. We analyzed joint observations from the 13 April 2019 event observed by LOw-Frequency ARray (LOFAR) at meter wavelengths, and the Siberian Radio Heliograph (SRH) and the Badary Broadband Microwave Spectropolarimeter (BBMS) spectropolarimeter in microwaves performed at the time of the second PSP perihelion. During a period without signatures of non-thermal energy release in X-ray emission, numerous type III and/or type J bursts were observed. During the same two hours we observed soft X-ray brightenings and the appearance of weak microwave emission in an abnormally narrow band around 6 GHz. At these frequencies the increasing flux is well above the noise level, reaching 9 sfu. In the LOFAR dynamic spectrum of 53−80 MHz a region is found that lasts about an hour whose emission is highly correlated with 6 GHz temporal profile. The flux peaks in the meter waves are well correlated with extreme UV (EUV) emission variations caused by repeated surges from the bright X-point. We argue that there is a common source of non-thermal electrons located in the tail of the active region, where two loop systems of very different sizes interacted. The frequencies of type III and/or type J bursts are in accordance with large loop heights around 400 Mm, obtained by the magnetic field reconstruction. The microwave coherent emission was generated in the low loops identified as bright X-ray points seen in soft X-ray and EUV images, produced by electrons with energies several tens of keV at about twice the plasma frequency

Glyphosate targets fish monoaminergic systems leading to oxidative stress and anxiety

Artículo científico indizadoGlyphosate is the active ingredient of some of the most highly produced and used herbicides worldwide. The intensive applications of glyphosate-based herbicides and its half-life in water lead to its presence in many aquatic ecosystems. Whereas recent studies have reported neurotoxic effects of glyphosate including autism- related effects, most of them used extremely high (mg/L to g/L) concentrations, so it is still unclear if chronic, low environmentally relevant concentrations of this compound (ng/L to μg/L) can induce neurotoxicity. In this study we analyzed the neurotoxicity of glyphosate in adult zebrafish after waterborne exposure to environmentally relevant concentrations (0.3 and 3 μg/L) for two weeks. Our data showed that exposed fish presented a significant impairment of exploratory and social behaviors consistent with increased anxiety. The anterior brain of the exposed fish presented a significant increase in dopamine and serotonin levels, as well as in the DOPAC/dopamine and homovanillic acid/dopamine turnover ratios. Moreover, the expression of genes involved in the dopaminergic system, as th1, th2, comtb, and scl6a3 was downregulated. Finally, the brain of exposed fish presented a significant increase in the catalase and superoxide dismutase activities, with a concomitant decrease of glutathione stores. These changes in the antioxidant defense system are consistent with the observed increase in oxidative stress, reflected by the increase in the levels of lipid peroxidation in the brain. The presented results show that current glyphosate concentrations commonly found in many aquatic ecosystems may have detrimental consequences on fish survival by decreasing exploration of the environment or altering social interactions. Furthermore, as zebrafish is also a vertebrate model widely used in human neurobehavioral studies, these results are relevant not only for environmental risk assessment, but also for understanding the risk of chronic low-dose exposures on human health.This work was supported by the Spanish Government with FEDER Funds (CTM2017-83242-R; D.R.) and the network of recognized research groups by the Catalan Government (2017 SGR_902). J.B. was supported by a Spanish fellowship PRE2018-083513. Mention of spe- cific products or trade names does not indicate endorsement by the US federal government