92 research outputs found

    Temperature dependence of binary and ternary recombination of H3+ ions with electron

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    We study binary and the recently discovered process of ternary He-assisted recombination of H3+ ions with electrons in a low temperature afterglow plasma. The experiments are carried out over a broad range of pressures and temperatures of an afterglow plasma in a helium buffer gas. Binary and He-assisted ternary recombination are observed and the corresponding recombination rate coefficients are extracted for temperatures from 77 K to 330 K. We describe the observed ternary recombination as a two-step mechanism: First, a rotationally-excited long-lived neutral molecule H3* is formed in electron-H3+ collisions. Second, the H3* molecule collides with a helium atom that leads to the formation of a very long-lived Rydberg state with high orbital momentum. We present calculations of the lifetimes of H3* and of the ternary recombination rate coefficients for para and ortho-H3+. The calculations show a large difference between the ternary recombination rate coefficients of ortho- and para-H3+ at temperatures below 300 K. The measured binary and ternary rate coefficients are in reasonable agreement with the calculated values.Comment: 15 page

    The pleistocene species pump past its prime:Evidence from European butterfly sister species

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: Read data are available from the ENA at PRJEB43082. Sequence alignments for the COI barcode locus were obtained from the dataset DS-EUGENMAP (dx.doi.org/10.5883/DS-EUGENMAP) on BOLD at www.boldsystems.org and were originally produced by Dincӑ et al., (2021). The script used for calculating diversity and divergence is available at https://github.com/samebdon/orthodiver/blob/master/orthodiver.py.The Pleistocene glacial cycles had a profound impact on the ranges and genetic make-up of organisms. Whilst it is clear that the contact zones that have been described for many sister taxa are secondary and have formed during the last interglacial, it is unclear when the taxa involved began to diverge. Previous estimates based on small numbers of loci are unreliable given the stochasticity of genetic drift and the contrasting effects of incomplete lineage sorting and gene flow on gene divergence. Here we use genome-wide transcriptome data to estimate divergence for 18 sister species pairs of European butterflies showing either sympatric or contact zone distributions. We find that in most cases species divergence predates the mid-Pleistocene transition or even the entire Pleistocene period. We also show that although post divergence gene flow is restricted to contact zone pairs, they are not systematically younger than sympatric pairs. This suggests that contact zones are not limited to the initial stages of the speciation process, but can involve notably old taxa. Finally, we show that mitochondrial and nuclear divergence are only weakly correlated and mitochondrial divergence is higher for contact-zone pairs.Biotechnology & Biological Sciences Research Council (BBSRC)Natural Environment Research Council (NERC)European Union Horizon 202

    Uncertainties and opportunities in delivering environmentally sustainable surgery:the surgeons' view

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    Surgery is a carbon‐heavy activity and creates a high volume of waste. Surgical teams around the world want to deliver more environmentally sustainable surgery but are unsure what to do and how to create change. There are many interventions available, but resources and time are limited. Capital investment into healthcare and engagement of senior management are challenging. However, frontline teams can change behaviours and drive wider change. Patients have a voice here too, as they would like to ensure their surgery does not harm their local community but are concerned about the effects on them when changes are made. Environmentally sustainable surgery is at the start of its journey. Surgeons need to rapidly upskill their generic knowledge base, identify which measures they can implement locally and take part in national research programmes. Surgical teams in the NHS have the chance to create a world‐leading programme that can bring change to hospitals around the world. This article provides an overview of how surgeons see the surgical team being involved in environmentally sustainable surgery

    Aluminum tolerance in maize is associated with higher MATE1 gene copy number

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    Genome structure variation, including copy number variation and presence/absence variation, comprises a large extent of maize genetic diversity; however, its effect on phenotypes remains largely unexplored. Here, we describe how copy number variation underlies a rare allele that contributes to maize aluminum (Al) tolerance. Al toxicity is the primary limitation for crop production on acid soils, which make up 50% of the world's potentially arable lands. In a recombinant inbred line mapping population, copy number variation of the Al tolerance gene multidrug and toxic compound extrusion 1 (MATE1) is the basis for the quantitative trait locus of largest effect on phenotypic variation. This expansion in MATE1 copy number is associated with higher MATE1 expression, which in turn results in superior Al tolerance. The three MATE1 copies are identical and are part of a tandem triplication. Only three maize inbred lines carrying the three-copy allele were identified from maize and teosinte diversity panels, indicating that copy number variation for MATE1 is a rare, and quite likely recent, event. These maize lines with higher MATE1 copy number are also Al-tolerant, have high MATE1 expression, and originate from regions of highly acidic soils. Our findings show a role for copy number variation in the adaptation of maize to acidic soils in the tropics and suggest that genome structural changes may be a rapid evolutionary response to new environments

    Banking union in historical perspective: the initiative of the European Commission in the 1960s-1970s

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    This article shows that planning for the organization of EU banking regulation and supervision did not just appear on the agenda in recent years with discussions over the creation of the eurozone banking union. It unveils a hitherto neglected initiative of the European Commission in the 1960s and early 1970s. Drawing on extensive archival work, this article explains that this initiative, however, rested on a number of different assumptions, and emerged in a much different context. It first explains that the Commission's initial project was not crisis-driven; that it articulated the link between monetary integration and banking regulation; and finally that it did not set out to move the supervisory framework to the supranational level, unlike present-day developments

    Gapless Assembly of Maize Chromosomes Using Long-Read Technologies

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    Creating gapless telomere-to-telomere assemblies of complex genomes is one of the ultimate challenges in genomics. We use two independent assemblies and an optical map-based merging pipeline to produce a maize genome (B73-Ab10) composed of 63 contigs and a contig N50 of 162 Mb. This genome includes gapless assemblies of chromosome 3 (236 Mb) and chromosome 9 (162 Mb), and 53 Mb of the Ab10 meiotic drive haplotype. The data also reveal the internal structure of seven centromeres and five heterochromatic knobs, showing that the major tandem repeat arrays (CentC, knob180, and TR-1) are discontinuous and frequently interspersed with retroelements

    L’intelligence comme dispositif de pouvoir

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    O objetivo do presente estudo, é compreender a inscrição individual e social de discursos usados por alunas, em diferentes posições de classe social, para explicar os seus sucessos académicos. Foram entrevistadas 19 alunas portuguesas do 11º ano de escolaridade provenientes das classes trabalhadora e alta, com elevado rendimento académico. A Análise Foucaudiana do Discurso aponta para a importância da posição de classe na construção dos sujeitos relativamente à sua conceção de inteligência e ao sucesso escolar. A inteligência funciona assim como um dispositivo de poder que regula as relações entre sujeitos de diferentes classes sociais.The objective of the present study is to understand the individual and social inscription of discourses used by students from different social class positions to explain their academic achievement. Nineteen portuguese students, from the 11th grade, with high academic performance and from the working class and upper class, in northern Portugal, were interviewed. Foucauldian Discourse Analysis points to the importance of class position in the construction of the subjects with respect to their concept of intelligence and academic success. Intelligence works as a power device that regulates the relations among subjects of different social classes.L’objectif de cette étude est de comprendre l’inscription individuelle et sociale des discours utilisés par les apprenantes dans différentes positions de classe sociale, pour expliquer leurs succès académiques. Dix-neuf apprenantes portugaises de la 11ème année de scolarité dotées d’un bon rendement scolaire issues des classes ouvrières et moyennes supérieures ont été interviewées. L’Analyse Foucaldienne du Discours souligne l’importance de la position de classe dans la construction des sujets concernant leur conception de l’intelligence et de la réussite scolaire. L’intelligence fonctionne aussi bien en tant que dispositif de pouvoir qui régit les relations entre les individus de différentes classes sociales.(undefined
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