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The virus responsible for COVID-19, SARS-CoV-2, is in the species SARS-like corona viruses. At 125 nm, it is slightly larger than influenza, SARS and MERS viruses. It is almost certainly a descendant from a bat corona virus of which there are many. The closest is a virus that originated from the Rhinolophus bat which is > 96% homologous with the current SARS-CoV-2 virus. It is only 79% homologous with the original SARS CoV [1]. The near identical gene sequences of 90 analysed cases from outside of China suggests it has likely emerged after a solitary species jump in early December 2019 from an unknown (likely mammalian) intermediate host [2]. Pangolins are an endangered ant-eating mammal from which scientists in Guangzhou have shown a coronavirus with 99% homology, with a receptor binding domain identical to that of SARS-CoV-2. However, this has not been confirmed, and, in addition, the pangolin's rarity means this may not be the only mammal involved. The symptoms of COVID-19 are fever, dry cough, fatigue, nasal congestion, sore throat and diarrhoea. On February 14th, the Chinese Center for Disease Control and Prevention (China CDC) published the first details of 44,672 confirmed cases, in the biggest study since the outbreak began [3]. Their findings show that COVID-19 was mild for 81% of patients and had an overall case fatality rate of 2.3%. Of those confirmed cases, only 2.2% were under 20 years old. Compared to adults, children generally present with much milder clinical symptoms. It is likely that future serological studies will show much asymptomatic disease in children. As opposed to H1N1, pregnant women do not appear to be at higher risk of severe disease. The severity of the disease appears to be associated with age, with the elderly most at risk; those over 80 years of age had a Case Fatality Rate (CFR) of 14.8%. The CFR was also increased in those with comorbidities including cardiovascular, diabetes, chronic respiratory disease, hypertension, and cancer. The cause of death is respiratory failure, shock or multiple organ failure.

Farmers around the world have recently experienced significant crop losses due to severe heat and drought. Such extreme weather events and the need to feed a rapidly growing population have raised concerns for global food security. While plant breeding has been very successful and has delivered today’s highly productive crop varieties, the rate of genetic improvement must double to meet the projected future demands. Here we discuss basic principles and features of crop breeding and how modern technologies could efficiently be explored to boost crop improvement in the face of increasingly challenging production conditions.

Microbes are found on us, within us and around us. They inhabit virtually every environment on the planet and the bacteria carried by an average human, mostly in their gut, outnumber human cells. The vast majority of microbes are harmless to us, and many play essential roles in plant, animal and human health. Others, however, are either obligate or facultative pathogens exerting a spectrum of deleterious effects on their hosts. Infectious diseases have historically represented the most common cause of death in humans until recently, exceeding by far the toll taken by wars or famines. From the dawn of humanity and throughout history, infectious diseases have shaped human evolution, demography, migrations and history.

Mesenchymal stem — or stromal — cells (MSCs) have been administered in hundreds of clinical trials for multiple indications, making them some of the most commonly used selected regenerative cells. Paradoxically, MSCs have also long remained the least characterized stem cells regarding native identity and natural function, being isolated retrospectively in long-term culture. Recent years have seen progress in our understanding of the natural history of these cells, and candidate native MSCs have been identified within fetal and adult organs. Beyond basic knowledge, deciphering the biology of innate MSCs may have important positive consequences for the therapeutic use of these cells.

Expansion microscopy (ExM) is a recently invented technology that uses swellable charged polymers, synthesized densely and with appropriate topology throughout a preserved biological specimen, to physically magnify the specimen 100-fold in volume, or more, in an isotropic fashion. ExM enables nanoscale resolution imaging of preserved samples on inexpensive, fast, conventional microscopes. How does ExM work? How good is its performance? How do you get going on using it? In this Q&A, we provide the answers to these and other questions about this new and rapidly spreading toolbox.

For the purpose of establishing vertical knowledge graph and auxiliary applications in the agricultural field, a set of agricultural knowledge graph construction methods, calculation frameworks and practical application systems are proposed. Firstly, the existing storage form and knowledge representation of knowledge in the agricultural field are integrated and regularized. On the basis of this data processing, the intelligent construction method of automatic and manual dual mode of knowledge graph in the agricultural field is proposed, and the key technology of entity relationship joint model to extract entity relationship and intelligent retrieval of irregular data. Then, similarity calculation will be used to perform entity knowledge fusion on knowledge graph in the agricultural field, making the graph more standardized, accurate and complete. A good graph is visualized and applied to the mainstream functions of intelligent question answering, which makes the whole system sort out the messy agricultural knowledge and apply it better to better assist learning and research.

Understanding the brain requires understanding behavior. New machine vision and learning techniques are poised to revolutionize our ability to analyze behaviors exhibited by animals in the laboratory. Here we describe one such method, Motion Sequencing (MoSeq), which combines three-dimensional (3D) imaging with unsupervised machine learning techniques to identify the syllables and grammar that comprise mouse body language. This Q&A situates MoSeq within the array of novel methods currently being developed for behavioral analysis, enumerates its relative strengths and weaknesses, and describes its future trajectory.

Infections that were common causes of death and disease in the pre-antibiotic era - rheumatic fever, syphilis, cellulitis and bacterial pneumonia - became treatable, and over the next 20 years most of the classes of antibiotics that find clinical use today were discovered and changed medicine in a profound way. In the past two decades we have witnessed: * the rise of so-called extended spectrum β-lactamases (ESBLs), which are mutants of enzymes that previously could only inactivate penicillins but now have gained activity against many cephalosporins; * carbapenemases such as KPC and NDM-1 that inactivate all β-lactam antibiotics; * plasmid-mediated (and thus horizontally disseminated) resistance to fluoroquinolone antibiotics; * the spread of virulent MRSA (methicillin-resistant Staphylococcus aureus) in the community; * the rise of multi-drug resistant Neisseria gonorrhoea; * the emergence and global dissemination of multi-drug resistant Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterobacteriaceae; * the spread of extensively drug resistant Mycobacterium tuberculosis; * the development of resistance to the two newest antibiotics to be approved for clinical use - daptomycin and linezolid. The rapidity of genome sequencing, the maturing of our knowledge of natural product biosynthesis, a growing understanding of the physical properties of ideal antibiotics, the development of new strategies to develop synthetic compounds with improved antibiotic properties, and the possibilities of synthetic biology combine to suggest that we are entering a highly productive period of antibiotic discovery.

Apoptosis is a form of programmed cell death that is carried out by proteolytic enzymes called caspases. Executioner caspase activity causes cells to shrink, bleb, and disintegrate into apoptotic bodies and has been considered a point of no return for apoptotic cells. However, relatively recent work has shown that cells can survive transient apoptotic stimuli, even after executioner caspase activation. This process is called anastasis. In this Q&A, we answer common questions that arise regarding anastasis, including how it is defined, the origin of the name, the potential physiological consequences, molecular mechanisms, and open questions for this new field of study.

Human language is unique among all forms of animal communication. It is unlikely that any other species, including our close genetic cousins the Neanderthals, ever had language, and so-called sign ‘language’ in Great Apes is nothing like human language. Language evolution shares many features with biological evolution, and this has made it useful for tracing recent human history and for studying how culture evolves among groups of people with related languages. A case can be made that language has played a more important role in our species’ recent (circa last 200,000 years) evolution than have our genes.