804 research outputs found

    A substantial fraction of phytoplankton-derived DON is resistant to degradation by a metabolically versatile, widely distributed marine bacterium

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    The capacity of bacteria for degrading dissolved organic nitrogen (DON) and remineralising ammonium is of importance for marine ecosystems, as nitrogen availability frequently limits productivity. Here, we assess the capacity of a widely distributed and metabolically versatile marine bacterium to degrade phytoplankton-derived dissolved organic carbon (DOC) and nitrogen. To achieve this, we lysed exponentially growing diatoms and used the derived dissolved organic matter (DOM) to support an axenic culture of Alteromonas sp.. Bacterial biomass (as particulate carbon and nitrogen) was monitored for 70 days while growth dynamics (cell count), DOM (DOC, DON) and dissolved nutrient concentrations were monitored for up to 208 days. Bacterial biomass increased rapidly within the first 7 days prior to a period of growth/death cycles potentially linked to rapid nutrient recycling. We found that ≈75% of the initial DOC and ≈35% of the initial DON were consumed by bacteria within 40 and 4 days respectively, leaving a significant fraction of DOM resilient to degradation by this bacterial species. The different rates and extents to which DOC and DON were accessed resulted in changes in DOM stoichiometry and the iterative relationship between DOM quality and bacterial growth over time influenced bacterial cell C:N molar ratio. C:N values increased to 10 during the growth phase before decreasing to values of ≈5, indicating a change from relative N-limitation/C-sufficiency to relative C-limitation/N-sufficiency. Consequently, despite its reported metabolic versatility, we demonstrate that Alteromonas sp. was unable to access all phytoplankton derived DOM and that a bacterial community is likely to be required. By making the relatively simple assumption that an experimentally derived fraction of DOM remains resilient to bacterial degradation, these experimental results were corroborated by numerical simulations using a previously published model describing the interaction between DOM and bacteria in marine systems, thus supporting our hypothesis

    On the relative roles of dynamics and chemistry governing the abundance and diurnal variation of low latitude thermospheric nitric oxide

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    We use data from two NASA satellites, the Thermosphere Ionosphere Energetics and Dynamics (TIMED) and the Aeronomy of Ice in the Mesosphere (AIM) satellites in conjunction with model simulations from the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM) to elucidate the key dynamical and chemical factors governing the abundance and diurnal variation of nitric oxide (NO) at near solar minimum conditions and low latitudes. This analysis was enabled by the recent orbital precession of the AIM satellite which caused the solar occultation pattern measured by the Solar Occultation for Ice Experiment (SOFIE) to migrate down to low and mid latitudes for specific periods of time. We use a month of NO data collected in January 2017 to compare with two versions of the TIME-GCM, one driven solely by climatological tides and analysis-derived planetary waves at the lower boundary and free running at all other altitudes, while the other is constrained by a high-altitude analysis from the Navy Global Environmental Model (NAVGEM)up to the mesopause. We also compare SOFIE data with a NO climatology from the Nitric Oxide Empirical Model (NOEM). Both SOFIE and NOEM yield peak NO abundances of around 4×107cm−3; however, the SOFIE profile peaks about 6-8 km lower than NOEM. We show that this difference is likely a local time effect; SOFIE being a dawn measurement and NOEM representing late morning/near noon. The constrained version of TIME-GCM exhibits a low altitude dawn peak while the model that is forced solely at the lower boundary and free running above does not. We attribute this difference due to a phase change in the semi-diurnal tide in the NAVGEM-constrained model causing descent of high NO mixing ratio air near dawn. This phase difference between the two models arises due to differences in the mesospheric zonal mean zonal winds. Regarding the absolute NO abundance, all versions of the TIME-GCM overestimate this. Tuning the model to yield calculated atomic oxygen in agreement with TIMED data helps, but is insufficient. Further, the TIME-GCM underestimates the electron density [e-] as compared with the International Reference Ionosphere empirical model. This suggests a potential conflict with the requirements of NO modeling and [e-] modeling since one solution typically used to increase model [e-] is to increase the solar soft X ray flux which would, in this case, worsen the NO model/data discrepancy

    Awareness and willingness to use HIV pre-exposure prophylaxis amongst gay and bisexual men in Scotland: implications for biomedical HIV prevention

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    Objectives:<p></p> To investigate the awareness of, and willingness to use, HIV Pre-Exposure Prophylaxis (PrEP), and willingness to take part in a PrEP study among gay and bisexual men in Scotland.<p></p> Methods:<p></p> Cross-sectional survey of 17 gay commercial venues in Glasgow and Edinburgh in May 2011 (N = 1515, 65.2% response rate); 1393 are included in the analyses.<p></p> Results:<p></p> Just under one-third of participants had heard of PrEP (n = 434; 31.2%), with awareness associated with being aged older than 35 years, talking to UAI partners about HIV, and with having had an HIV or STI test in the previous 12 months. Around half were willing to take part in a PrEP study (n = 695; 49.9%) or to take PrEP on a daily basis (n = 756; 54.3%). In multivariate analysis, willingness to take PrEP was associated with lower levels of education, regular gay scene attendance, ‘high-risk’ unprotected anal intercourse (UAI) and testing for HIV or STI in the previous 12 months. Reasons for not wanting to participate in a PrEP study or take PrEP included perceptions of low personal risk of HIV and concerns with using medication as an HIV prevention method.<p></p> Conclusions:<p></p> There is a willingness to engage in new forms of HIV prevention and research amongst a significant number of gay and bisexual men in Scotland. Future biomedical HIV interventions need to consider the links between sexual risk behaviour, testing, and potential PrEP use

    On the increase in thermal diffusivity caused by the perovskite to post-perovskite phase transition and its implications for mantle dynamics

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    The thermal diffusivity (κ) of perovskite and post-perovskite CaIrO3 has been measured, at elevated pressure and temperatures up to 600 °C, using the X-radiographic Ångström method. At high temperatures we find that the thermal diffusivity of post-perovskite is slightly below twice that of isochemical perovskite over the temperature range investigated. Assuming a similar effect occurs in MgSiO3 post-perovskite, the effect of the contrasting thermal transport properties between perovskite and post-perovskite on mantle dynamics has been investigated using simple two-dimensional convection models. These show a reduction in extent and increase in depth of post-perovskite lenses, as well as increased core–mantle-boundary heat-flux, broader upwellings and more vigorous downwellings when compared to the reference, constant a, case

    Review of developments in person-centred healthcare

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    Brendan McCormack - ORCID: 0000-0001-8525-8905 https://orcid.org/0000-0001-8525-8905Tanya McCance - ORCID: 0000-0002-9787-2627 https://orcid.org/0000-0002-9787-2627In recent years, there has been a shift in orientation towards person-centredness as part of a global move towards humanising and centralising the person within healthcare. Person-centredness, underpinned by robust philosophical and theoretical concepts, has an increasingly solid footprint in policy and practice, but research and education lag behind. This article considers the emergence of person-centredness, including person-centred care, and how it is positioned in healthcare policy around the world, while recognising a dominant philosophical positioning in Western philosophy, concepts and theories. Second, the evolution of person-centred healthcare over the past five years is reviewed. Published evidence of person-centred healthcare developments is drawn on, as well as information gathered from key stakeholders who engaged with the partner organisations in an Erasmus+ project to develop a European person-centred healthcare curriculum framework. Five themes are identified, which underpin the literature and stakeholder perspectives: Policy development for transformation Participatory strategies for public engagement Healthcare integration and coordination strategies Frameworks for practice Process and outcome measurement These themes reflect the World Health Organization’s global perspective on people-centred and integrated healthcare, and give some indication of development priorities as person-centred healthcare systems continue to be developed.https://doi.org/10.19043/ipdj.10Suppl2.00310pubpubSuppl

    Developing philosophical and pedagogical principles for a pan-European person-centred curriculum framework

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    Brendan McCormack - ORCID: 0000-0001-8525-8905 https://orcid.org/0000-0001-8525-8905Background: In the associated article in this special issue of the International Practice Development Journal, Phelan et al. (2020) offer an analysis of the global positioning of person-centredness from a strategic policy perspective. This second article, an international person-centred education curriculum development initiative, builds on that foundational work. It outlines the systematic, rigorous processes adopted by academics from five European countries to analyse stakeholder data, theoretically frame the data, and thereby identify philosophical and pedagogical principles to inform the development of person-centred curriculum frameworks.Aim: To identify key principles that have the potential to create an international curriculum framework for the education of person-centred healthcare practitioners.Methods: A hermeneutic praxis methodological approach was used, where multiple rounds of data analyses were conducted. These were initially undertaken in each country, then collaboratively with partners, while engaging with other forms of evidence.Findings: The project group generated a set of principles embedded in four philosophical dimensions: (i) transformative; (ii) co-constructed; (iii) relational; and (iv) pragmatic. The purpose of the curriculum was identified as being transformative, facilitating journeying through knowing, doing, being and becoming a competent and committed person-centred practitioner. A person-centred curriculum is built on a philosophy of pragmatism, adopts a co-constructionist approach to curriculum design and implementation, and encourages connectivity with self, other persons and contexts. Pedagogical principles, aligned to the four philosophical dimensions, identified the required learning environment, and the learning, teaching and assessment approaches required to educate person-centred healthcare practitioners.Conclusion: This article represents steps to foster a more focused and engaging way of implicitly and explicitly embedding person-centred care in curricula. Our theoretical framework has enabled us to consider the different layers of practice while staying true to the purpose of curriculum design. The presentation of the framework in this article makes it available for wider critique to those with an interest in this area of study.Implications for practice: The draft framework provides an opportunity for curriculum teams to critically reflect on and have dialogue around current curricula Person-centred curricula have the potential to improve service-user experiences of care Prepared person-centred practitioners will contribute to person-centred cultures Students and practitioners will experience person-centredness Practitioners will be bold and innovativehttps://doi.org/10.19043/ipdj.10Suppl2.00410pubpubSuppl

    A pragmatic, multicentre, randomised controlled trial comparing stapled haemorrhoidopexy to traditional excisional surgery for haemorrhoidal disease (eTHoS): study protocol for a randomised controlled trial

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    Background: Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical, quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more effective and more cost-effective, compared with TH. Methods/Design: eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part. The primary clinical and economic outcomes are QoL profile (area under the curve derived from the EuroQol Group’s 5 Dimension Health Status Questionnaire (EQ-5D) at all assessment points) and incremental cost per quality adjusted life year (QALY) based on the responses to the EQ-5D at 24 months. The secondary outcomes include a comparison of the SF-36 scores, pain and symptoms sub-domains, disease recurrence, complication rates and direct and indirect costs to the National Health Service (NHS). A sample size of n =338 per group has been calculated to provide 90% power to detect a difference in the mean area under the curve (AUC) of 0.25 standard deviations derived from EQ-5D score measurements, with a two-sided significance level of 5%. Allowing for non-response, 400 participants will be randomised per group. Randomisation will utilise a minimisation algorithm that incorporates centre, grade of haemorrhoidal disease, baseline EQ-5D score and gender. Blinding of participants and outcome assessors is not attempted. Discussion: This is one of the largest trials of its kind. In the United Kingdom alone, 29,000 operations for haemorrhoidal disease are done annually. The trial is therefore designed to give robust evidence on which clinicians and health service managers can base management decisions and, more importantly, patients can make informed choices. Trial registration: Current Controlled Trials ISRCTN80061723 (assigned 8 March 2010

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Distinct Origin of the Y and St Genome in Elymus Species: Evidence from the Analysis of a Large Sample of St Genome Species Using Two Nuclear Genes

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    Previous cytological and single copy nuclear genes data suggested the St and Y genome in the StY-genomic Elymus species originated from different donors: the St from a diploid species in Pseudoroegneria and the Y from an unknown diploid species, which are now extinct or undiscovered. However, ITS data suggested that the Y and St genome shared the same progenitor although rather few St genome species were studied. In a recent analysis of many samples of St genome species Pseudoroegneria spicata (Pursh) À. Löve suggested that one accession of P. spicata species was the most likely donor of the Y genome. The present study tested whether intraspecific variation during sampling could affect the outcome of analyses to determining the origin of Y genome in allotetraploid StY species. We also explored the evolutionary dynamics of these species.Two single copy nuclear genes, the second largest subunit of RNA polymerase II (RPB2) and the translation elongation factor G (EF-G) sequences from 58 accessions of Pseudoroegneria and Elymus species, together with those from Hordeum (H), Agropyron (P), Australopyrum (W), Lophopyrum (E(e)), Thinopyrum (E(a)), Thinopyrum (E(b)), and Dasypyrum (V) were analyzed using maximum parsimony, maximum likelihood and Bayesian methods. Sequence comparisons among all these genomes revealed that the St and Y genomes are relatively dissimilar. Extensive sequence variations have been detected not only between the sequences from St and Y genome, but also among the sequences from diploid St genome species. Phylogenetic analyses separated the Y sequences from the St sequences.Our results confirmed that St and Y genome in Elymus species have originated from different donors, and demonstrated that intraspecific variation does not affect the identification of genome origin in polyploids. Moreover, sequence data showed evidence to support the suggestion of the genome convergent evolution in allopolyploid StY genome species
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