179566 research outputs found
Sort by
The evolution of reproduction in Ediacaran–Cambrian metazoans
No full textThe evolution of reproductive style is a fundamental aspect of metazoan life history but has not been explored holistically through the Ediacaran–Cambrian rise of metazoans. Recent molecular clock analyses based on only unequivocal metazoan fossil calibrations suggest that Porifera were present by at least 590 million years ago (Ma), all major eumetazoan clades originated in the mid–late Ediacaran, and bilaterians were probably present by the late Ediacaran. An alternating pelagic larval (potentially for dispersal) and benthic adult life cycle appears to be an ancestral feature of metazoans. A compilation of inferred reproductive styles from the fossil record reveals that the low-competition, deep-water communities of the Ediacaran Avalon macrofossil assemblage (ca. 575 to 560 Ma) had current-borne sexually produced larval with both local (non-planktotrophic, with no feeding) and more widespread (planktotrophic, with feeding) dispersal followed by vegetative growth. By ca. 560 Ma, White Sea assemblage communities in shallow settings show dense aggregations, which were often dominated by single populations of episodic sexually produced larval spatfalls. Some taxa may show potential larval philopatry. By 550 Ma, with the rise of biomineralization and colonisation of shallow marine carbonate settings, the ability to encrust hard substrates, create multiple branches via budding, and rudimentary mutual attachment of inferred clones, first appear. The dominant apparent mode of reproduction throughout the Ediacaran was therefore via current-borne sexually produced larvae followed by asexual reproduction, via either budding, fragmentation or fission. In these communities where biotic interactions were limited, this enabled colonisation of newly available soft and hard substrates followed by rapid growth. Early Cambrian communities showed increased endemism, enhanced trophic interactions and widespread macropredation. By the early Cambrian Fortunian stage (ca. 535 Ma), gonochorism (separate sexes) may have been present in priapulid worms. During Cambrian Stage 2 (ca. 532 Ma), internal fertilisation probably appeared in molluscs but widespread planktotrophy did not appear until the latest Cambrian/early Ordovician. Mutual attachment of diverse skeletal taxa became more common, particularly within reefs. Evidence for egg brooding and parental care in arthropods had appeared by the early Stage 3 (ca. 518 Ma). While reproductive styles were independently acquired, this overall pattern suggests a shift both to higher fecundity and to higher quality offspring in some groups during the Ediacaran–Cambrian Radiation, driven by increasing biotic interactions, including the rise of macropredation
Evaluating tropospheric nitrogen dioxide in UKCA using OMI satellite retrievals over south and east Asia
No full textWe compare tropospheric column nitrogen dioxide (NO2) in the United Kingdom Chemistry and Aerosol (UKCA) model version 11.0 with satellite measurements from NASA's Earth Observing System (EOS) Aura satellite Ozone Monitoring Instrument (OMI) to investigate the seasonality and trends of tropospheric NO2 over south and east Asia (S and E Asia). UKCA is the atmospheric composition component of the UK Earth System Model (UKESM). UKCA was run with nudged meteorology, producing hourly output over S and E Asia for 2005–2015. OMI averaging kernels have been applied to the model hourly data sampled at Aura's local overpass time of 13:45 LT ± 15 min to allow for consistent model–data comparison. Background UKCA and OMI tropospheric column NO2 typically ranges between 0×1015 and 2×1015 . Diurnal cycles and vertical profiles of the tropospheric NO2 column in UKCA show that the daily minimum tropospheric column NO2 occurs around the satellite overpass time. UKCA captures the seasonality but overestimates NO2 by a factor of ∼ 2.5, especially during winter over eastern China and north India, at times and locations with high aerosol loadings. Heterogeneous chemistry is represented in the version of UKCA used here as uptake of N2O5 on internally generated sulfate aerosol. However, aerosol surface area may be underestimated in polluted locations, contributing to overestimation of NO2. In addition, the model may underestimate emissions of volatile organic compounds (VOCs) and associated peroxy acetyl nitrate (PAN) formation, leading to insufficient long-range transport of oxidised nitrogen and also contributing to overestimation of NO2 over polluted regions and underestimation over remote regions. Quantifying and understanding discrepancies in modelled NO2 warrant further investigation as they propagate into modelling of multiple environmental issues
Automatic reply:Another university is possible
No full textThis chapter takes the form of an email exchange among the authors between February and June 2023 – a period characterized by an unprecedented level of disruption caused by ongoing industrial action at UK universities. Reflecting on the theme ‘Making liveable (STS) worlds through reflexive methods’, it is punctuated by real life – travel, delays, family holidays, doubts, detours, culs-de-sac, unfulfilled promises, flights of fancy, jokes, conflicting priorities, strikes and out-of-office messages – and as such embodies something of the intersecting worlds in which we live. As it precludes other possibilities, the chapter’s form becomes a material meditation on the challenges of building liveable worlds together through reflexive practices in the present moment
Epistemic normativity as autotelic:Why suspension and judgment aren’t like archery
No full textWe can evaluate what people do in relation to the effects of their doings. Often, the effect is the result of the agent trying to bring about some goal, and we evaluate what they have done by asking how well they have pursued the goal and whether they have achieved it. If someone is trying to bake a loaf of bread, for example, we can assess how well they did by asking how well they followed the recipe and whether the result matches what they were trying to achieve. This is not the only way to assess a doing, however: we can also assess it by comparing its effects to a constitutive aim of the doing, which the agent may not have in mind when they perform the deed. For example, if a chess-player moves their bishop, we can assess that move by relating it to the constitutive aim of chess moves—checkmate—even if that’s not what the person is trying to achieve with the particular move. Either way, when we evaluate a doing by assessing how effective it is at bringing about some goal—which, importantly, may never come about—our evaluations are, as we shall say, heterotelic. The evaluations are telic, because they evaluate their target relative to ends, and they are heterotelic, because the standard of evaluation is something different than a conception of the doing itself. The standard of evaluation will commonly be a state of affairs that can potentially be brought about by the doing
Metapopulation-level analyses reveal positive fitness consequences of immigration in a small bird
No full textAbstract Dispersal links eco-evolutionary dynamics of subpopulations in fragmented landscapes and may play a crucial role in the viability of populations by increasing individual fitness and subpopulation growth rates. However, knowledge of individual fitness of immigrants and residents and their offspring at the local and metapopulation levels is often lacking due to the difficulty of quantifying fitness in geographically structured wild populations, which requires extensive field efforts. A comprehensive dataset that includes more than 15?years of individual capture-mark-recapture information and a high-resolution SNP-based pedigree from an insular wild house sparrow (Passer domesticus) metapopulation, was used to examine the fitness consequences of successful immigration for parent and offspring generations, and assess the relative contributions of immigrants and residents to the local pool of recruits versus individuals that recruited in other populations within the metapopulation. We show that immigrants produced more recruiting offspring annually and during their lifetime than residents. Moreover, we found that hybrid recruits (produced by immigrant-resident parents) had higher adult survival and produced more recruiting offspring during their lifetime than recruits produced by two resident or two immigrant parents. Additionally, although contributions to the local pool of recruits did not differ between immigrant and resident parents during their lifetime, immigrant parents produced more offspring that recruited in other populations than resident parents. Our results indicate that the benefits of being an immigrant last at least through the first offspring generation. Such positive fitness effects of immigrants may improve local population viability as well as metapopulation viability. Our study shows the importance of quantifying fitness of successful immigrants at a wide geographic scale in structured populations, because it may be difficult to a priori predict whether dispersers and residents contribute similarly or differently to the dynamics at local population and metapopulation levels
The potential impacts of vector host species fidelity on zoonotic arbovirus transmission
Get PDFThe interaction between vector host preference and host availability on vector blood feeding behaviour has important implications for the transmission of vector-borne pathogens. However, to our knowledge, the effect of bias towards feeding on the same host species from which a first meal was taken, termed fidelity, has not been quantified. Using a mathematical model we showed that vector fidelity to the host species they take a first blood meal from leads to non-homogeneous mixing between hosts and vectors. Taking Japanese encephalitis virus (JEV) as a case study, we investigated how vector preference for amplifying vs dead-end hosts and fidelity can influence JEV transmission. We show that in regions where pigs (amplifying hosts) are scarce compared to cattle (dead-end hosts preferred by common JEV vectors), JEV could still be maintained through vector fidelity. Our findings demonstrate the importance of considering fidelity as a potential driver of transmission, particularly in scenarios such as Bangladesh and India where the composition of the host community might initially suggest that transmission is not possible.</p
Comparative analysis of transcription initialisation principles in early avian development
Get PDFChickens have undergone intense domestication and serve as a significant global source of protein through meat and egg production. The unique advantages of species like chicken and quail, with their small body size, short generation times, ease of manipulation, and genetic diversity, make them especially relevant for studying domestication traits and gene regulation. Despite significant advances in annotating the chicken genome, available datasets for quail remain limited, making it challenging to distinguish differences in gene expression between these two closely related species. To address this gap, we collected domestic chicken and Japanese quail embryos at four early embryonic stages and generated a new CAGE dataset. Based on the results of CAGEflow pipeline, we conducted a comprehensive comparative analysis of their genomes to investigate mechanisms of transcription initialisation. Through this approach, we were able to determine and map transcription start sites between two species at base pair resolution and thus determine the effect on gene expression. To further analyse promoter sequence architecture, we applied a recently developed SeqArchR tool using non-negative matrix factorisation to cluster promoter sequences into characteristic architectures de novo. We identified novel motifs downstream of the transcription start site that had not been previously described. These motifs were present in both species, and we hypothesise that they play a role in transcription initiation. Taken together, our results represent the first comparative analysis of embryonic promoter usage between these two species and highlight how speciation influences gene regulation during development
Genomics-led approach to drug testing in models of undifferentiated pleomorphic sarcoma
Get PDFUndifferentiated pleomorphic sarcoma (UPS) is a rare cancer with limited systemic treatment options and poor outcomes. To seek novel therapeutic interventions, we undertook mutational analysis of twenty UPS patient tumours, four established UPS cell lines and three patient-derived xenograft (PDX) models. Frequently mutated genes were uncommon; in contrast copy number (CN) events were common with CN gain frequently observed at genes including JUN, EGFR and CDK6 and loss at WNT8B, RB1 and PTEN. Analysis of overlapping genomic changes between patient tumours and PDX models or cell lines revealed druggable events. A selected panel of drugs targeting these was analysed in in vitro UPS models demonstrating that the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib is synergistic in combination with the fibroblast growth factor receptor (FGFR) inhibitor infigratinib. This was further confirmed to be efficacious in an ex vivo tumour slice model. Taken together, our resultsdemonstrate the rationale for utilising genomic data to identify drug classes targeting druggable events in low-prevalence cancers and indicate that trametinib alone or in combination with infigratinib should be further explored for clinical UPS management
Cell morphogenesis: How to turn yeast into Cerberus
Get PDFPioneering research in the black yeast A. pullulans begins to reveal the mechanistic elements of its cell polarity network that allow this multinucleate fungus to grow multiple buds simultaneously, in contrast to the budding yeast that strictly enforces the uniqueness of its bud
Managing menopause transition in the workplace:The double-edged sword of flexible work
Get PDFDespite a growing body of literature around menopause at work, our understanding of how menopause symptoms may impact employees over time is limited. Using a longitudinal sample of 679 cis-women, we predicted that the changes in the severity of psychological and physical menopause symptoms would lead to changes in burnout and perceived job performance over a period of six months. Drawing from resource theories, we further explored whether the usefulness of flexible work may moderate these relationships. Our findings showed that women who experienced greater intensification of menopause symptoms experienced an increase in burnout, and women whose symptoms became less intense experienced a decrease in burnout. We also found that those who considered flexible work more useful, experienced a positive change in their perceived job performance, despite suffering from the intensified physical symptoms. Those who perceived such flexible work to be less useful, however, did not exhibit a significant change in their performance over time. In-depth qualitative findings on a sub-sample of 53 women provided nuanced explanations for these results, including exposing a double-edged sword of working flexibly to manage menopause symptoms and potentially detrimental unintended consequences of flexible work during menopause transition
Access Repository Dashboard
Do you manage Edinburgh Research Explorer? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!