23 research outputs found
Coupling, Reinforcement, and Speciation
During the process of speciation, populations may diverge for traits and at their underlying loci that contribute barriers to gene flow. These barrier traits and barrier loci underlie individual barrier effects, by which we mean the contribution that a barrier locus or trait-or some combination of barrier loci or traits-makes to overall isolation. The evolution of strong reproductive isolation typically requires the origin of multiple barrier effects. Critically, it also requires the coincidence of barrier effects; for example, two barrier effects, one due to assortative mating and the other due to hybrid inviability, create a stronger overall barrier to gene flow if they coincide than if they distinguish independent pairs of populations. Here, we define "coupling" as any process that generates coincidence of barrier effects, resulting in a stronger overall barrier to gene flow. We argue that speciation research, both empirical and theoretical, needs to consider both the origin of barrier effects and the ways in which they are coupled. Coincidence of barrier effects can occur either as a by-product of selection on individual barrier effects or of population processes, or as an adaptive response to indirect selection. Adaptive coupling may be accompanied by further evolution that enhances individual barrier effects. Reinforcement, classically viewed as the evolution of prezygotic barriers to gene flow in response to costs of hybridization, is an example of this type of process. However, we argue for an extended view of reinforcement that includes coupling processes involving enhancement of any type of additional barrier effect as a result of an existing barrier. This view of coupling and reinforcement may help to guide development of both theoretical and empirical research on the process of speciation
Ecological speciation in sympatric palms: 2. Pre- and post-zygotic isolation
We evaluated reproductive isolation in two species of palms (Howea) that have evolved sympatrically on Lord Howe Island (LHI, Australia). We estimated the strength of some pre- and post-zygotic mechanisms in maintaining current species boundaries. We found that flowering time displacement between species is consistent across in and ex situ common gardens and is thus partly genetically determined. On LHI, pre-zygotic isolation due solely to flowering displacement was 97% for Howea belmoreana and 80% for H. forsteriana; this asymmetry results from H. forsteriana flowering earlier than H. belmoreana and being protandrous. As expected, only a few hybrids (here confirmed by genotyping) at both juvenile and adult stages could be detected in two sites on LHI, in which the two species grow intermingled (the Far Flats) or adjacently (Transit Hill). Yet, the distribution of hybrids was different between sites. At Transit Hill, we found no hybrid adult trees, but 13.5% of younger palms examined there were of late hybrid classes. In contrast, we found four hybrid adult trees, mostly of late hybrid classes, and only one juvenile F1 hybrid in the Far Flats. This pattern indicates that selection acts against hybrids between the juvenile and adult stages. An in situ reciprocal seed transplant between volcanic and calcareous soils also shows that early fitness components (up to 36 months) were affected by species and soil. These results are indicative of divergent selection in reproductive isolation, although it does not solely explain the current distribution of the two species on LHI
Ecological speciation in sympatric palms: 1. Gene expression, selection and pleiotropy
Ecological speciation requires divergent selection, reproductive isolation and a genetic mechanism to link the two. We examined the role of gene expression and coding sequence evolution in this process using two species of Howea palms that have diverged sympatrically on Lord Howe Island, Australia. These palms are associated with distinct soil types and have displaced flowering times, representing an ideal candidate for ecological speciation. We generated large amounts of RNA-Seq data from multiple individuals and tissue types collected on the island from each of the two species. We found that differentially expressed loci as well as those with divergent coding sequences between Howea species were associated with known ecological and phenotypic differences, including response to salinity, drought, pH and flowering time. From these loci, we identified potential 'ecological speciation genes' and further validate their effect on flowering time by knocking out orthologous loci in a model plant species. Finally, we put forward six plausible ecological speciation loci, providing support for the hypothesis that pleiotropy could help to overcome the antagonism between selection and recombination during speciation with gene flow
Autoantibodies against type I IFNs in patients with life-threatening COVID-19
Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men
TERMINOLOGY EXTRACTION FROM LOG FILES
In many domains, the log files generated by digital systems contain important information on the conditions and configurations of systems. Information Extraction from these log files is an essential phase in information systems, which manage the production line. In the case of Integrated Circuit designs, log files generated by design tools are not exhaustively exploited. Although these log files are written in English, they usually do not respect the grammar and the structures of natural language. Moreover, such logs have a heterogeneous and evolving structure. According to features of such textual data, applying the classical methods of information extraction is not an easy task, more particularly for terminology extraction. In this paper, we thus introduce our approach EXTERLOG to extract the terminology from such log files. We also aim at knowing if POS tagging of such log files is a relevant approach for terminology extraction.
Desarrollo de las habilidades de expresiĂłn oral mediante los juegos verbales en los estudiantes de la I.E. NÂș 45 del Distrito de PachacĂștec, Ica.
Trabajo academicoEl presente proyecto de innovación es de naturaleza pedagógica porque consiste en aplicar los juegos verbales para mejorar la expresión oral en los estudiantes, ya que la comunicación oral es la entrada a la socialización y al medio a través del cual los niños y niñas pueden manifestar sus ideas, opiniones, propuestas, dudas, inquietudes y
sentimientos, asĂ como transmitir informaciĂłn y conocimientos.
Durante el proceso de planificaciĂłn y ejecuciĂłn del proyecto se abordarĂĄ la dimensiĂłn institucional porque estarĂĄ colocado en un objetivo estratĂ©gico del Proyecto Educativo Institucional (PEI) y las actividades y acciones en el Plan Anual de Trabajo (PAT). En la dimensiĂłn administrativa las actividades serĂĄn financiadas con aporte de la instituciĂłn, en la dimensiĂłn pedagĂłgica se capacitarĂĄ a los docentes, los mismos que planificarĂĄn y ejecutarĂĄn sesiones de aprendizaje con estrategias innovadoras para los estudiantes, tambiĂ©n se fortalecerĂĄn con los cĂrculos de interaprendizaje, donde los docentes intercambiarĂĄn sus experiencias pedagĂłgicas. HabrĂĄ recojo, anĂĄlisis y sistematizaciĂłn de
información durante el monitoreo y acompañamiento a las docentes. Esto nos ayudarå a tomar decisiones pertinentes para resolver el problema. Asimismo, en la dimensión comunitaria se involucrarå a los padres de familia en las actividades educativas de sus hijos y a otros aliados estratégicos que nos apoyen a mejorar los aprendizajes
Existence of a pattern of reproductive character displacement in Homobasidiomycota but not in Ascomycota
Toward the integration of speciation research
Speciation researchâthe scientific field focused on understanding the origin and diversity of speciesâhas a long and complex history. While relevant to one another, the specific goals and activities of speciation researchers are highly diverse, and scattered across a collection of different perspectives. Thus, our understanding of speciation will benefit from efforts to bridge scientific findings and the diverse people who do the work. In this paper, we outline two ways of integrating speciation research: (i) scientific integration, through the bringing together of ideas, data, and approaches; and (ii) social integration, by creating ways for a diversity of researchers to participate in the scientific process. We then discuss five challenges to integration: (i) the multidisciplinary nature of speciation research, (ii) the complex language of speciation; (iii) a bias toward certain study systems; (iv) the challenges of working across scales; and (v) inconsistent measures and reporting standards. We provide practical steps that individuals and groups can take to help overcome these challenges, and argue that integration is a team effort in which we all have a role to play
Electroweak measurements in electronâpositron collisions at w-boson-pair energies at lep
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121524.pdf (preprint version ) (Open Access
Euclid. IV. The NISP Calibration Unit
International audienceThe near-infrared calibration unit (NI-CU) onboard Euclid's Near-Infrared Spectrometer and Photometer (NISP) is the first astronomical calibration lamp based on light-emitting diodes (LEDs) to be operated in space. Euclid is a mission in ESA's 'Cosmic Vision 2015-2025' framework, to explore the dark universe and provide a next-level characterisation of the nature of gravitation, dark matter, and dark energy. Calibrating photometric and spectrometric measurements of galaxies to better than 1.5% accuracy in a survey homogeneously mapping ~14000 deg^2 of extragalactic sky requires a very detailed characterisation of near-infrared (NIR) detector properties, as well their constant monitoring in flight. To cover two of the main contributions - relative pixel-to-pixel sensitivity and non-linearity characteristics - as well as support other calibration activities, NI-CU was designed to provide spatially approximately homogeneous (=100 from ~15 ph s^-1 pixel^-1 to >1500 ph s^-1 pixel^-1. For this functionality, NI-CU is based on LEDs. We describe the rationale behind the decision and design process, describe the challenges in sourcing the right LEDs, as well as the qualification process and lessons learned. We also provide a description of the completed NI-CU, its capabilities and performance as well as its limits. NI-CU has been integrated into NISP and the Euclid satellite, and since Euclid's launch in July 2023 has started supporting survey operations