The past decade has seen a major increase in the study of noncoding RNAs (ncRNAs). However, there remains a great deal of confusion and debate over the levels of functionality and mechanisms of ...action of the majority of these new transcripts. This Opinion article addresses several of these issues, focusing particularly on long ncRNAs (lncRNAs). We reemphasize the unique abilities of RNAs to form myriad structures as well as to interact with other RNAs, DNA, and proteins, which provide them with unique and powerful abilities. One of these, the ability to interact sequence specifically with DNA, has been largely overlooked. Accumulating evidence suggests that evolution has taken advantage of RNA’s properties via the rapid acquisition of new noncoding genes in testes, with subsequent gains of function in other tissues. This amplification process appears to be one of the major forces driving metazoan evolution and diversity.
The majority of RNAs transcribed by the human genome are in the form of long noncoding RNAs (lncRNAs).
The number of lncRNAs with validated functions is growing exponentially. lncRNAs are associated with virtually all diseases.
The number of lncRNA genes is proportional to organismal complexity.
lncRNAs that regulate epigenetic processes act as DNA sequence-specific guides.
The majority of lncRNAs are probably localized in the cytoplasm.
The tissue with the highest levels and diversity of noncoding RNA expression is the testis.
The majority of new lncRNA genes are believed to have evolved in the testis.
We describe three-dimensional magnetohydrodynamical modelling of powerful radio galaxies in realistic poor cluster environments. This modelling extends our earlier work on the hydrodynamics of radio ...galaxies as a function of their cluster environment to consider the magnetic field configuration in the lobes and its observational consequences, using a realistic model for the magnetic field in the intracluster medium, very high density contrast in the lobes and high numerical resolution. We confirm, now with a realistic magnetic field model, that lobes have characteristic trajectories in the radio power/linear size diagram which depend strongly on their environment. We investigate the detailed evolution of polarized emission, showing that the lobes evolve from the initially ordered field configuration imposed by our boundary conditions to one in which the longitudinal field comes to dominate. We obtain simulated observations of polarization whose properties are quantitatively consistent with observations. The highly spatially intermittent magnetic field also reproduces the observation that inverse-Compton emission from lobes is much smoother than synchrotron. Our simulations allow us to study the depolarizing effect of the external medium on the lobes, and so to demonstrate that Faraday depolarization from environments of the type we consider can reproduce the integrated fractional polarization properties of large samples and the observed preferential depolarization of the receding lobe.
We present results from two suites of simulations of powerful radio galaxies in poor cluster environments, with a focus on the formation and evolution of the radio lobes. One suite of models uses ...relativistic hydrodynamics and the other relativistic magnetohydrodynamics; both are set up to cover a range of jet powers and velocities. The dynamics of the lobes are shown to be in good agreement with analytical models and with previous numerical models, confirming in the relativistic regime that the observed widths of radio lobes may be explained if they are driven by very light jets. The ratio of energy stored in the radio lobes to that put into the intracluster gas is seen to be the same regardless of jet power, jet velocity or simulation type, suggesting that we have a robust understanding of the work done on the ambient gas by this type of radio source. For the most powerful jets, we at times find magnetic field amplification by up to a factor of 2 in energy, but mostly the magnetic energy in the lobes is consistent with the magnetic energy injected. We confirm our earlier result that for jets with a toroidally injected magnetic field, the field in the lobes is predominantly aligned with the jet axis once the lobes are well developed, and that this leads to radio flux anisotropies of up to a factor of about two for mature sources. We reproduce the relationship between 151 MHz luminosity and jet power determined analytically in the literature.
We have carried out two-dimensional, axisymmetric, hydrodynamic numerical modelling of the evolution of radio galaxy lobes. The emphasis of our work is on including realistic hot-gas environments in ...the simulations and on establishing what properties of the resulting radio lobes are independent of the choice of environmental properties and of other features of the models such as the initial jet Mach number. The simulated jet power we use is chosen so that we expect the inner parts of the lobes to come into pressure balance with the external medium on large scales; we show that this leads to the expected departure from self-similarity and the formation of characteristic central structures in the hot external medium. The work done by the expanding radio lobes on the external hot gas is roughly equal to the energy stored in the lobes for all our simulations once the lobes are well established. We show that the external pressure at the lobe mid-point is a reasonable estimate of the internal (lobe) pressure, with only a weak dependence on the environmental parameters; on the other hand, the predicted radio emission from a source of a given physical size has a comparatively strong dependence on the environment in which the lobe resides, introducing an order of magnitude of scatter into the jet power versus radio luminosity relationship. X-ray surface brightness and temperature visualizations of our simulations bear a striking resemblance to observations of some well-studied radio galaxies.
A
bstract
The discovery of the Higgs boson by the LHC experiments ATLAS and CMS has marked a milestone for particle physics. Yet, there are still many open questions that cannot be answered within ...the Standard Model (SM). For example, the generation of the observed matter-antimatter asymmetry in the universe through baryogenesis can only be explained qualitatively in the SM. A simple extension of the SM compatible with the current theoretical and experimental constraints is given by the 2-Higgs-Doublet Model (2HDM) where a second Higgs doublet is added to the Higgs sector. We investigate the possibility of a strong first order electroweak phase transition in the CP-conserving 2HDM type I and type II where either of the CP-even Higgs bosons is identified with the SM-like Higgs boson. The renormalisation that we apply on the loop-corrected Higgs potential allows us to efficiently scan the 2HDM parameter space and simultaneously take into account all relevant theoretical and up-to-date experimental constraints. The 2HDM parameter regions found to be compatible with the applied constraints and a strong electroweak phase transition are analysed systematically. Our results show that there is a strong interplay between the requirement of a strong phase transition and collider phenomenology with testable implications for searches at the LHC.
The COVID-19 pandemic went hand in hand with what some have called a “(mis)infodemic” about the virus on social media. Drawing on partisan motivated reasoning and partisan selective sharing, this ...study examines the influence of political viewpoints, anxiety, and the interactions of the two on believing and willingness to share false, corrective, and accurate claims about COVID-19 on social media. A large-scale 2 (emotion: anxiety vs relaxation) × 2 (slant of news outlet: MSNBC vs Fox News) experimental design with 719 US participants shows that anxiety is a driving factor in belief in and willingness to share claims of any type. Especially for Republicans, a state of heightened anxiety leads them to believe and share more claims. Our findings expand research on partisan motivated reasoning and selective sharing in online settings, and enhance the understanding of how anxiety shapes individuals’ processing of risk-related claims in issue contexts with high uncertainty.
The observation that long noncoding RNAs (lncRNAs) represent the majority of transcripts in humans has led to a rapid increase in interest and study. Most of this interest has focused on their roles ...in the nucleus. However, increasing evidence is beginning to reveal even more functions outside the nucleus, and even outside cells. Many of these roles are mediated by newly discovered properties, including the ability of lncRNAs to interact with lipids, membranes, and disordered protein domains, and to form differentially soluble RNA–protein sub-organelles. This review explores the possibilities enabled by these new properties and abilities, such as likely roles in exosome formation and function.
lncRNAs play important nucleating and structural roles in a growing number of phase-separating ribonucleoprotein complexes referred to here as microbodies.
Microbody formation is nucleated by long, repetitive, unspliced, and non-polyadenylated lncRNAs referred to as arcRNAs.
lncRNAs can interact with membranes and specific phospholipids (PIP3).
lncRNAs can target proteins to membranes.
lncRNAs are important functional components of exosomes and are likely to play roles in their formation and function.
Abstract
Feedback from active galactic nuclei (AGN) has become a major component in simulations of galaxy evolution, in particular for massive galaxies. AGN jets have been shown to provide a large ...amount of energy and are capable of quenching cooling flows. Their impact on the host galaxy, however, is still not understood. Subgrid models of AGN activity in a galaxy evolution context so far have been mostly focused on the quenching of star formation. To shed more light on the actual physics of the 'radio mode' part of AGN activity, we have performed simulations of the interaction of a powerful AGN jet with the massive gaseous disc () of a high-redshift galaxy. We spatially resolve both the jet and the clumpy, multi-phase interstellar medium (ISM) and include an explicit star formation model in the simulation. Following the system over more than 107 yr, we find that the jet activity excavates the central region, but overall causes a significant change to the shape of the density probability distribution function and hence the star formation rate due to the formation of a blast wave with strong compression and cooling in the ISM. This results in a ring- or disc-shaped population of young stars. At later times, the increase in star formation rate also occurs in the disc regions further out since the jet cocoon pressurizes the ISM. The total mass of the additionally formed stars may be up to for one duty cycle. We discuss the details of this jet-induced star formation (positive feedback) and its potential consequences for galaxy evolution and observable signatures.
Abstract
In May 2014, the National Institutes of Health (NIH) stated its intent to “require applicants to consider sex as a biological variable (SABV) in the design and analysis of NIH-funded ...research involving animals and cells.” Since then, proposed research plans that include animals routinely state that both sexes/genders will be used; however, in many instances, researchers and reviewers are at a loss about the issue of sex differences. Moreover, the terms sex and gender are used interchangeably by many researchers, further complicating the issue. In addition, the sex or gender of the researcher might influence study outcomes, especially those concerning behavioral studies, in both animals and humans. The act of observation may change the outcome (the “observer effect”) and any experimental manipulation, no matter how well-controlled, is subject to it. This is nowhere more applicable than in physiology and behavior. The sex of established cultured cell lines is another issue, in addition to aneuploidy; chromosomal numbers can change as cells are passaged. Additionally, culture medium contains steroids, growth hormone, and insulin that might influence expression of various genes. These issues often are not taken into account, determined, or even considered. Issues pertaining to the “sex” of cultured cells are beyond the scope of this Statement. However, we will discuss the factors that influence sex and gender in both basic research (that using animal models) and clinical research (that involving human subjects), as well as in some areas of science where sex differences are routinely studied. Sex differences in baseline physiology and associated mechanisms form the foundation for understanding sex differences in diseases pathology, treatments, and outcomes. The purpose of this Statement is to highlight lessons learned, caveats, and what to consider when evaluating data pertaining to sex differences, using 3 areas of research as examples; it is not intended to serve as a guideline for research design.
While the use of deep learning is a valuable technology for automatic detection systems for medical data and images, the biofouling community is still lacking an analytical tool for the detection and ...counting of diatoms on samples after short-term field exposure. In this work, a fully convolutional neural network was implemented as a fast and simple approach to detect diatoms on two-channel (fluorescence and phase-contrast) microscopy images by predicting bounding boxes. The developed approach performs well with only a small number of trainable parameters and a F1 score of 0.82. Counting diatoms was evaluated on a data set of 600 microscopy images of three different surface chemistries (hydrophilic and hydrophobic) and is very similar to counting by humans while demanding only a fraction of the analysis time.
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