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Magnetic reconnection is a key mechanism involved in solar eruptions and is also a prime possibility to heat the low corona to millions of degrees. Here, we present ultra-high-resolution extreme ultraviolet observations of persistent null-point reconnection in the corona at a scale of about 390 km over one hour observations of the Extreme-Ultraviolet Imager on board Solar Orbiter spacecraft. The observations show formation of a null-point configuration above a minor positive polarity embedded within a region of dominant negative polarity near a sunspot. The gentle phase of the persistent null-point reconnection is evidenced by sustained point-like high-temperature plasma (about 10 MK) near the null-point and constant outflow blobs not only along the outer spine but also along the fan surface. The blobs appear at a higher frequency than previously observed with an average velocity of about 80 km s −1 and life-times of about 40 s. The null-point reconnection also occurs explosively but only for 4 minutes, its coupling with a mini-filament eruption generates a spiral jet. These results suggest that magnetic reconnection, at previously unresolved scales, proceeds continually in a gentle and/or explosive way to persistently transfer mass and energy to the overlying corona. Magnetic reconnection is a fundamental energy release mechanism in space and laboratory plasmas. Here, the authors show persistent magnetic null-point reconnection in the solar corona at a scale of about 390 km.

\"Book summary for this bilingual (English-French) anthology of early modern fictitious catalogues, selections were made from a multitude of texts, from the genre's beginnings (Rabelais's satirical catalogue of the Library of St.-Victor (1532)) to its French and Dutch specimens from around 1700. In thirteen chapters, written by specialists in the field, diverse texts containing fictitious booklists are presented and contextualized. Several of these texts are well known (by authors such as Fischart, Doni, and Le Noble), others - undeservedly - are less known, or even unrecorded. The anthology is preceded by a literary historical and theoretical introduction addressing the parodic and satirical aspects of the genre, and its relationship to other genres: theatre, novel, and pamphlet. Contributors include: Helwi Blom, Tobias Bulang, Raphaèel Cappellen, Ronnie Ferguson, Dirk Geirnaert, Jelle Koopmans, Marijke Meijer Drees, Claudine Nâedelec, Patrizia Pellizzari, Anne-Pascale Pouey-Mounou, Paul J. Smith, and Dirk Werle\"-- Provided by publisher.

We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multimodel mean OH concentration is overestimated by 5 to 10% but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high north–south OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34 %). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6 %) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the change in global mean tropospheric CO and NOx burdens (1CO/1NOx, approximately represents changes in OH sinks versus changes in OH sources) in the models, pointing to a need for better constraints on natural precursor emissions and on the chemical mechanisms in the current generation of chemistry-climate models. For the 1980 to 2000 period, we find that climate warming and a slight increase in mean OH (3.5±2.2 %) leads to a 4.3±1.9% decrease in the methane lifetime. Analysing sensitivity simulations performed by 10 models, we find that preindustrial to presentday climate change decreased the methane lifetime by about four months, representing a negative feedback on the climate system. Further, we analysed attribution experiments performed by a subset of models relative to 2000 conditions with only one precursor at a time set to 1860 levels. We find that global mean OH increased by 46.4±12.2% in response to preindustrial to present-day anthropogenic NOx emission increases, and decreased by 17.3±2.3 %, 7.6±1.5 %, and 3.1±3.0% due to methane burden, and anthropogenic CO, and NMVOC emissions increases, respectively.

نشر كتاب آدم سميث (ثروة الامم) للمرة الأولى عام 1776م، وأقر الجميع على الفور تقريبا بأهميته الجوهرية والحاسمة في فهم علم الاقتصاد،وعد سفرا ضخما. ومثلما اشار أوروك، فإن القارئ يحتاج لفهم كتاب ثروة الامم إلى قراءة متأنية لكتاب ضخم آخر ألفه سميث قبله وهو كتاب (نظرية العواطف الأخلاقية). لكن القارئ الآن ليس مضطرا لتحمل عناء قراءة أي منهما فقد قام أوروك بالمهمة نيابة عنه. في هذا الكتاب الممتع، يظهر لنا أوروك، بأسلوبه الرشيق الساخر، السبب الذي جعل سميث معاصرا ووثيق الصلة بالواقع الراهن، ولماذا يحظى تقسيم العمل وحرية التجارة والسعي وراء المصلحة الشخصية بأهمية حيوية وأساسية لسعادة البشر ورفاهيتهم. ثم يفجر الكاتب قنبلته ليعلن أن سميث أبعد مايكون عن الرمز المجسد لقسوة الرأسمالية.

The type VI secretion system (T6SS) is a nanomachine used by many bacteria to drive a toxin-laden needle into other bacterial cells. Although the potential to influence bacterial competition is clear, the fitness impacts of wielding a T6SS are not well understood. Here we present a new agent-based model that enables detailed study of the evolutionary costs and benefits of T6SS weaponry during competition with other bacteria. Our model identifies a key problem with the T6SS. Because of its short range, T6SS activity becomes self-limiting, as dead cells accumulate in its way, forming \"corpse barriers\" that block further attacks. However, further exploration with the model presented a solution to this problem: if injected toxins can quickly lyse target cells in addition to killing them, the T6SS becomes a more effective weapon. We tested this prediction with single-cell analysis of combat between T6SS-wielding Acinetobacter baylyi and T6SS-sensitive Escherichia coli. As predicted, delivery of lytic toxins is highly effective, whereas nonlytic toxins leave large patches of E. coli alive. We then analyzed hundreds of bacterial species using published genomic data, which suggest that the great majority of T6SS-wielding species do indeed use lytic toxins, indicative of a general principle underlying weapon evolution. Our work suggests that, in the T6SS, bacteria have evolved a disintegration weapon whose effectiveness often rests upon the ability to break up competitors. Understanding the evolutionary function of bacterial weapons can help in the design of probiotics that can both establish well and eliminate problem species.

Bacteria often live in diverse communities where the spatial arrangement of strains and species is considered critical for their ecology. However, a test of this hypothesis requires manipulation at the fine scales at which spatial structure naturally occurs. Here we develop a droplet-based printing method to arrange bacterial genotypes across a sub-millimetre array. We print strains of the gut bacterium Escherichia coli that naturally compete with one another using protein toxins. Our experiments reveal that toxin-producing strains largely eliminate susceptible non-producers when genotypes are well-mixed. However, printing strains side-by-side creates an ecological refuge where susceptible strains can persist in large numbers. Moving to competitions between toxin producers reveals that spatial structure can make the difference between one strain winning and mutual destruction. Finally, we print different potential barriers between competing strains to understand how ecological refuges form, which shows that cells closest to a toxin producer mop up the toxin and protect their clonemates. Our work provides a method to generate customised bacterial communities with defined spatial distributions, and reveals that micron-scale changes in these distributions can drive major shifts in ecology. The spatial arrangement of bacterial strains and species within microbial communities is considered crucial for their ecology. Here, Krishna Kumar et al. use a droplet-based printing method to arrange different bacterial genotypes across a sub-millimetre array, and show that micron-scale changes in spatial distributions can drive major shifts in ecology.

BackgroundPrevious studies have shown that the incidence of idiopathic pulmonary fibrosis (IPF) is rising in the UK and USA. Death registrations and primary care data were used to determine the current trends in IPF incidence in the UK. Because routine clinical data sets were used, the term IPF clinical syndrome (IPF-CS) is used to describe individuals in this study.MethodsAge- and stratum-specific death registration rates between 1968 and 2008 were calculated and these were applied to the 2008 population to generate annual standardised expected number of deaths. Annual mortality rate ratios were calculated using Poisson regression. Computerised primary care records were used to determine incidence rates of IPF-CS between 2000 and 2008 stratified by age, sex and geographical region, and survival rates between calendar periods were compared.ResultsAnnual death certificate recording of IPF-CS rose sixfold across the study period from 0.92 per 100 000 in the 1968–1972 calendar periods to 5.10 per 100 000 in the 2006–2008 calendar period, and were higher in men and the older age groups. The incidence of IPF-CS in primary care increased by 35% from 2000 to 2008, with an overall incidence rate of 7.44 per 100 000 person-years (95% CI 7.12 to 7.77). Incidence was higher in men, the older population and in Northwest England.ConclusionsThe incidence of IPF-CS in primary care and registered deaths from this cause in the UK continues to rise in the 21st century. The current findings suggest that there are >5000 new cases diagnosed each year in the UK.