A revised catalogue of Galactic supernova remnants (SNRs) is presented, along with some simple statistics of their properties. Six new SNRs have been added to the catalogue since the previous ...published version from 2014, and six entries have been removed, as they have been identified as
H ii
regions, leaving the number of entries in the catalogue at 294. Some simple statistics of the remnants in the catalogue, and the selection effects that apply, are discussed, along with some recently proposed Galactic SNR candidates.
Supernova remnants (SNRs) in the Galaxy are an important source of energy injection into the interstellar medium, and also of cosmic rays. Currently there are 294 known SNRs in the Galaxy, and their ...distribution with Galactocentric radius is of interest for various studies. Here I discuss some of the statistics of Galactic SNRs, including the observational selection effects that apply, and difficulties in obtaining distances for individual remnants from the ‘
$\Sigma$
–D’ relation. Comparison of the observed Galactic longitude distribution of a sample of bright Galactic SNRs – which are not strongly affected by selection effects – with those expected from models is used to constrain the Galactic distribution of SNRs. The best-fitting power-law/exponential model is more concentrated towards the Galactic Centre than the widely used distribution obtained by Case & Bhattacharya.
This survey study examines individual-level changes in alcohol use in US adults and associated negative consequences, from before to during the coronavirus disease 2019 (COVID-19) pandemic.
The bioactive sphingolipid metabolites ceramide and sphingosine-1-phosphate (S1P) are a recent addition to the lipids accumulated in obesity and have emerged as important molecular players in ...metabolic diseases. Here we summarize evidence that dysregulation of sphingolipid metabolism correlates with pathogenesis of metabolic diseases in humans. This review discusses the current understanding of how ceramide regulates signaling and metabolic pathways to exacerbate metabolic diseases and the Janus faces for its further metabolite S1P, the kinases that produce it, and the multifaceted and at times opposing actions of S1P receptors in various tissues. Gaps and limitations in current knowledge are highlighted together with the need to further decipher the full array of their actions in tissue dysfunction underlying metabolic pathologies, pointing out prospects to move this young field of research toward the development of effective therapeutics.
Sphingolipid metabolites, particularly ceramide and sphingosine-1-phosphate, have emerged as important mediators in the development of metabolic diseases. In this review, Green et al. discuss the multifacted, tissue-specific roles of these sphingolipid metabolites and how their dysregulation contributes to the pathogenesis of metabolic diseases.
Influenza, a highly contagious respiratory tract infection, affects millions of adults and children each year. Several high-risk populations include children, the elderly, the immunocompromised, and ...recently the obese. Given the dramatic rise in obesity over the past few decades, this increased risk for influenza infection poses a serious public health threat because nearly 500 million adults and children worldwide are classified as obese. Obesity impairs the immune response to influenza and influenza vaccination through alterations of the cellular immune system. Compared with vaccinated healthy-weight adults, vaccinated obese adults have twice the risk of influenza or influenza-like illness despite equal serological response to vaccination. This challenges the current standard of protection for influenza and suggests that further vaccination methods or therapeutics are required to combat this virulent respiratory virus.
There has been much progress in genomics in the ten years since a draft sequence of the human genome was published. Opportunities for understanding health and disease are now unprecedented, as ...advances in genomics are harnessed to obtain robust foundational knowledge about the structure and function of the human genome and about the genetic contributions to human health and disease. Here we articulate a 2011 vision for the future of genomics research and describe the path towards an era of genomic medicine.
ABSTRACT
The Galactic source G2.4+1.4 is an optical and radio nebula containing an extreme Wolf–Rayet star. At one time, this source was regarded as a supernova remnant, because of its apparent ...non-thermal radio spectrum, although this was based on limited observations. Subsequent observations instead supported a flat, optically thin thermal radio spectrum for G2.4+1.4, and it was identified as a photoionized, mass-loss bubble, not a supernova remnant. Recently, however, it has been claimed that this source has a non-thermal integrated radio spectrum. I discuss the integrated radio flux densities available for G2.4+1.4 from a variety of surveys, and show that it has a flat spectrum at gigahertz frequencies (with a spectral index α of 0.02 ± 0.08, where flux density S scales with frequency ν as S ∝ ν−α).
Phagocytic cells of the immune system must constantly survey for, recognize, and efficiently clear the billions of cellular corpses that arise as a result of development, stress, infection, or normal ...homeostasis. This process, termed efferocytosis, is critical for the prevention of autoimmune and inflammatory disorders, and persistence of dead cells in tissue is characteristic of many human autoimmune diseases, notably systemic lupus erythematosus. The most notable characteristic of the efferocytosis of apoptotic cells is its 'immunologically silent' response. Although the mechanisms by which phagocytes facilitate engulfment of dead cells has been a well-studied area, the pathways that coordinate to process the ingested corpse and direct the subsequent immune response is an area of growing interest. The recently described pathway of LC3 (microtubule-associated protein 1A/1B-light chain 3)-associated phagocytosis (LAP) has shed some light on this issue. LAP is triggered when an extracellular particle, such as a dead cell, engages an extracellular receptor during phagocytosis, induces the translocation of autophagy machinery, and ultimately LC3 to the cargo-containing phagosome, termed the LAPosome. In this review, we will examine efferocytosis and the impact of LAP on efferocytosis, allowing us to reimagine the impact of the autophagy machinery on innate host defense mechanisms.
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