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Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays at 100 MeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, and SOHO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections (CMEs), electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting reconnection of magnetic field lines as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s lower ionosphere. While flare scenarios have slowly converged over the past decades, every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

Although some pharmacokinetic studies have tested a higher than usual amount of grapefruit juice to determine the maximum effect, this should not be interpreted to mean that a relevant pharmacokinetic interaction will only occur with high levels of consumption. Indeed, a single usual amount (i.e., 200-250 mL juice or a whole grapefruit) has sufficient potency to cause a pertinent pharmacokinetic interaction.8,11,12 For example, felodipine combined with such a quantity of grapefruit had an average systemic drug concentration that was 3-fold that seen with water.8,11With twice the amount of grapefruit, there was only a modestly greater increase in the systemic concentration of felodipine, showing that a near-maximal pharmacokinetic interaction had already occurred with the consumption of the single quantity.11 With repeated ingestion of grapefruit (250 mL of juice, 3 times/d for 6 d), a single dose of felodipine increased to 5 times the systemic concentration seen with water, suggesting that frequent consumption of a usual quantity daily augmented the pharmacokinetic effect moreso than the lone quantity.8 Taking atorvastatin in the evening and drinking grapefruit juice in the morning (300 mL/d from a specific lot prepared by the Florida Department of Citrus) resulted in drug serum concentrations that were 119%-126% of those seen with no consumption of grapefruit, with no evidence of skeletal muscle toxicity (e.g., elevated creatine phosphokinase, myalgia).43 In addition, pravastatin does not produce a pharmacokinetic interaction with grapefruit,39,40 rosuvastatin is eliminated unchanged,35 and fluvastatin is metabolized by an enzyme (cytochrome P450 2C9) that is not affected by grapefruit.35 Although staggering the ingestion of atorvastatin and grapefruit may reduce risk, substituting pravastatin, rosuvastatin or fluvastatin, or eliminating grapefruit juice from the diet, appears more preferable. We conducted a comprehensive search of the PubMed database for all available scientifically valid evidence using the keyword \"grapefruit\" and the following additional terms: \"drug,\" \"drug interaction,\" \"pharmacokinetics,\" \"cytochrome P450,\" \"CYP3A4,\" \"case report\" or \"review.\" In addition, we obtained product monographs and prescribing information for drugs recently introduced (i.e., in the last 4 yr) to the Canadian market. We assessed the following sections of these documents for relevant information: \"Summary Product Information,\" \"Warnings and Precautions,\" \"Contraindications,\" \"Adverse Reactions,\" \"Drug Interactions\" and \"Action and Clinical Pharmacology.\" We identified 190 relevant publications (161 articles from PubMed; 29 product monographs or prescribing information sheets). Most of the information was from randomized controlled clinical trials (n = 102). The measured outcome from these studies was change in drug pharmacokinetics, and this was used to assess the potential for adverse clinical consequences.

We present a new analysis framework called “Correlation Analysis Tool using the Schrödinger equation” (CATS) which computes the two-particle femtoscopy correlation function C(k), with k being the relative momentum for the particle pair. Any local interaction potential and emission source function can be used as an input and the wave function is evaluated exactly. In this paper we present a study on the sensitivity of C(k) to the interaction potential for different particle pairs: p–p, p–Λ, K-–p, K+–p, p–Ξ- and Λ–Λ. For the p–p Argonne v18 and Reid Soft-Core potentials have been tested. For the other pair systems we present results based on strong potentials obtained from effective Lagrangians such as χEFT for p–Λ, Jülich models for K(K¯)–N and Nijmegen models for Λ–Λ. For the p–Ξ- pairs we employ the latest lattice results from the HAL QCD collaboration. Our detailed study of different interacting particle pairs as a function of the source size and different potentials shows that femtoscopic measurements can be exploited in order to constrain the final state interactions among hadrons. In particular, small collision systems of the order of 1 fm, as produced in pp collisions at the LHC, seem to provide a suitable environment for quantitative studies of this kind.

Solar type V radio bursts are associated with type III bursts. Several processes have been proposed to interpret the association, electron distribution, and emission. We present the observation of a unique type V event observed by e-CALLISTO on 7 May 2021. The type V radio emission follows a group of U bursts. Unlike the unpolarized U bursts, the type V burst is circularly polarized, leaving room for a different emission process. Its starting edge drifts to higher frequency four times slower than the descending branch of the associated U burst. The type V processes seem to be ruled by electrons of lower energy. The observations conform to a coherent scenario where a dense electron beam drives the two-stream instability (causing type III emission) and, in the nonlinear stage, becomes unstable to another instability, previously known as the electron firehose instability (EFI). The secondary instability scatters some beam electrons into velocities perpendicular to the magnetic field and produces, after particle loss, a trapped distribution prone to electron cyclotron masering (ECM). A reduction in beaming and the formation of an isotropic halo are predicted for electron beams continuing to interplanetary space, possibly observable by Parker Solar Probe and Solar Orbiter.

Rac1 Is Required for Cardiomyocyte Apoptosis During Hyperglycemia E. Shen 1 , 2 , Yanwen Li 3 , Ying Li 1 , 2 , Limei Shan 1 , 2 , Huaqing Zhu 1 , 2 , Qingping Feng 1 , 2 , 4 , J. Malcolm O. Arnold 1 , 2 , 4 and Tianqing Peng 1 , 2 , 5 1 Critical Illness Research, Lawson Health Research Institute, University of Western Ontario, London, Ontario, Canada; 2 Department of Medicine, University of Western Ontario, London, Ontario, Canada; 3 Department of Microbiology, Imperial College London, London, U.K; 4 Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; 5 Department of Pathology, University of Western Ontario, London, Ontario, Canada. Corresponding author: Tianqing Peng, tpeng2{at}uwo.ca . E.S. and Y.L. contributed equally to this study. Abstract OBJECTIVE Hyperglycemia induces reactive oxygen species (ROS) and apoptosis in cardiomyocytes, which contributes to diabetic cardiomyopathy. The present study was to investigate the role of Rac1 in ROS production and cardiomyocyte apoptosis during hyperglycemia. RESEARCH DESIGN AND METHODS Mice with cardiomyocyte-specific Rac1 knockout (Rac1-ko) were generated. Hyperglycemia was induced in Rac1-ko mice and their wild-type littermates by injection of streptozotocin (STZ). In cultured adult rat cardiomyocytes, apoptosis was induced by high glucose. RESULTS The results showed a mouse model of STZ-induced diabetes, 7 days of hyperglycemia-upregulated Rac1 and NADPH oxidase activation, elevated ROS production, and induced apoptosis in the heart. These effects of hyperglycemia were significantly decreased in Rac1-ko mice or wild-type mice treated with apocynin. Interestingly, deficiency of Rac1 or apocynin treatment significantly reduced hyperglycemia-induced mitochondrial ROS production in the heart. Deficiency of Rac1 also attenuated myocardial dysfunction after 2 months of STZ injection. In cultured cardiomyocytes, high glucose upregulated Rac1 and NADPH oxidase activity and induced apoptotic cell death, which were blocked by overexpression of a dominant negative mutant of Rac1, knockdown of gp91 phox or p47 phox , or NADPH oxidase inhibitor. In type 2 diabetic db/db mice, administration of Rac1 inhibitor, NSC23766, significantly inhibited NADPH oxidase activity and apoptosis and slightly improved myocardial function. CONCLUSIONS Rac1 is pivotal in hyperglycemia-induced apoptosis in cardiomyocytes. The role of Rac1 is mediated through NADPH oxidase activation and associated with mitochondrial ROS generation. Our study suggests that Rac1 may serve as a potential therapeutic target for cardiac complications of diabetes. Footnotes E.S. is currently affiliated with The 6 th People's Hospital, Shanghai Jiaotong University, Shanghai, China. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Received May 7, 2008. Accepted July 1, 2009. © 2009 by the American Diabetes Association.

About 10 μs after the Big Bang, the universe was filled—in addition to photons and leptons—with strong-interaction matter consisting of quarks and gluons, which transitioned to hadrons at temperatures close to kT = 150 MeV and densities several times higher than those found in nuclei. This quantum chromodynamics (QCD) matter can be created in the laboratory as a transient state by colliding heavy ions at relativistic energies. The different phases in which QCD matter may exist depend for example on temperature, pressure or baryochemical potential, and can be probed by studying the emission of electromagnetic radiation. Electron–positron pairs emerge from the decay of virtual photons, which immediately decouple from the strong interaction, and thus provide information about the properties of QCD matter at various stages. Here, we report the observation of virtual photon emission from baryon-rich QCD matter. The spectral distribution of the electron–positron pairs is nearly exponential, providing evidence for a source of temperature in excess of 70 MeV with constituents whose properties have been modified, thus reflecting peculiarities of strong-interaction QCD matter. Its bulk properties are similar to the dense matter formed in the final state of a neutron star merger, as apparent from recent multimessenger observation.

Our recent study demonstrated that Rac1 and NADPH oxidase activation contributes to cardiomyocyte apoptosis in short-term diabetes. This study was undertaken to investigate if disruption of Rac1 and inhibition of NADPH oxidase would prevent myocardial remodeling in chronic diabetes. Diabetes was induced by injection of streptozotocin in mice with cardiomyocyte-specific Rac1 knockout and their wild-type littermates. In a separate experiment, wild-type diabetic mice were treated with vehicle or apocynin in drinking water. Myocardial hypertrophy, fibrosis, endoplasmic reticulum (ER) stress, inflammatory response, and myocardial function were investigated after 2 months of diabetes. Isolated adult rat cardiomyocytes were cultured and stimulated with high glucose. In diabetic hearts, NADPH oxidase activation, its subunits' expression, and reactive oxygen species production were inhibited by Rac1 knockout or apocynin treatment. Myocardial collagen deposition and cardiomyocyte cross-sectional areas were significantly increased in diabetic mice, which were accompanied by elevated expression of pro-fibrotic genes and hypertrophic genes. Deficiency of Rac1 or apocynin administration reduced myocardial fibrosis and hypertrophy, resulting in improved myocardial function. These effects were associated with a normalization of ER stress markers' expression and inflammatory response in diabetic hearts. In cultured cardiomyocytes, high glucose-induced ER stress was inhibited by blocking Rac1 or NADPH oxidase. Rac1 via NADPH oxidase activation induces myocardial remodeling and dysfunction in diabetic mice. The role of Rac1 signaling may be associated with ER stress and inflammation. Thus, targeting inhibition of Rac1 and NADPH oxidase may be a therapeutic approach for diabetic cardiomyopathy.

Aedes aegypti, the primary vector of dengue virus, is predominantly considered an urban mosquito, especially in the Americas, where its reemergence began in cities after the end of continent-wide eradication campaigns. The results of our study diverge from this narrative, demonstrating the recent and widespread rural invasion of Ae. aegypti along major shipping routes in the northern Peruvian Amazon between the major cities of Iquitos, Pucallpa, and Yurimaguas. Using prokopack aspirators to conduct indoor mosquito collections, we identified Ae. aegypti populations in 29 of 30 sites surveyed across a rural to urban gradient and quantified Ae. aegypti adult metrics. In multiple instances, adult Ae. aegypti indices in rural villages were equal to or greater than indices in dengue-endemic cities, suggesting the entomological risk level in some rural areas is sufficient to support dengue transmission. Fourteen rural sites were sampled in transects from the community river port into town. In seven of these sites, houses closer to the port were significantly more likely to be infested with Ae. aegypti adults than houses further from the ports, and four additional sites showed a similar trend. This pattern suggests that Ae. aegypti is still actively invading many rural sites by adult Ae. aegypti disembarking from boats at the port, finding nearby oviposition sites, and advancing stepwise towards the interior, with sections of towns still Ae. aegypti- free. Only one site showed a strong signal of invasion via the egg or larval stage, with a focus of Ae. aegypti far removed from the port. The widespread infestation of Ae. aegypti in rural areas is a major public health threat given the far distance of communities to hospital care. It is important to implement control measures now before the mosquito gains a stronger foothold in zones of active invasion.