171 research outputs found

    Phytoplankton and microbial plankton of the Northeast Atlantic Shelf

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    The Northeast Atlantic Shelf region includes the sites from all coastal waters of Ireland, the Irish Sea, and western Scottish and Norwegian Sea waters. The region was defined by WGPME to include locations on the northern margin of Europe that were outside the North Sea/English Channel influence. The character of sites in the region are shallow, coastal-water sites ranging from sheltered bays on the south coast of Ireland and fjordic sea lochs of Scotland to fully exposed locations on the west coasts of Ireland and Scotland. Bathymetry of the region ranges from shallow embayments to regions of shallow, exposed continental-shelf waters. The topography of the shelf drops rapidly to 80–100 m within 20 km of the coast, where it extends to the shelf edge as a relatively flat plateau. Time-series of phytoplankton data from the Atlantic Shelf exhibit a typical seasonal pattern of temperate waters, with considerable geographical and temporal variation. The well-mixed winter conditions lead to a region-wide strong spring bloom observed at all sites. The ensuing decrease in nutrient levels lead to a variable summer period characterized by stratified conditions in coastal areas and periodic blooms of mixed or occasionally monospecific diatom and dinoflagellate composition. The growth period tails off in autumn, when a secondary bloom may occur in response to increased mixing and breakdown of the summer thermocline. The seasonal cycle returns to a quiescent winter phase, with generally mixed conditions, light limitation, and increased nutrients return. Seasonal stabilization and destabilization of the water column in this region accounts for most of the natural variation in both phytoplankton species composition and biomass

    Oxalate-Induced Damage to Renal Tubular Cells

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    Our own studies and those of others have shown that the incidence of calcium oxalate stones and plaques is markedly increased by nephrotoxins. The possible role of oxalate as a nephrotoxin has not been fully appreciated. However, recent studies in experimental animals and in cultured cells support this possibility. The results of these studies led us to hypothesize that hyperoxaluria promotes stone formation in several ways: by providing a substrate for the formation of the most common form of renal stones, calcium oxalate stones, and by inducing damage to renal epithelial cells. Damaged cells in turn would produce an environment favorable for crystal retention and provide membranous debris that promotes crystal nucleation, aggregation and adherence. The present report summarizes evidence for oxalate nephrotoxicity and discusses the potential importance of oxalate toxicity in the pathogenesis of stone disease

    Impacts of climate change on harmful algal blooms

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    High biomass Harmful Algal Blooms (HABs) such as Karenia mikimotoi and shellfish toxin producing HAB species continue to be observed in UK and Republic of Ireland waters. Regional differences continue to be seen in the distribution of HABs in UK and RoI waters with impacts mainly observed in the south and west coast of Ireland and regions in the UK with a strong Atlantic influence, e.g. Regions 1, 3, 4, 6 and 7. There is little monitoring aside from the continuous plankton recorder (CPR) in Region 8. The impacts from HABs in Wales, Northern Ireland and the Isle of Man are generally low. Since the last MCCIP report card was issued, blooms of Karenia mikimotoi have caused problems in Ayrshire, Scotland, and also in the north-west coast of Ireland where concerns about the quantity of dead wild fish washing on shore during an event in Ireland in 2012 resulted in two beaches being closed to the public. No clear trend that can be attributed to climate change can be observed in the incidence of shellfish toxin producing HABs since the last report card was issued. During the last two years the incidence of some shellfish toxins has continued to decrease (e.g. paralytic shellfish poisoning toxins in Scotland). High concentrations of yessotoxins (YTX) and azaspiracids (AZAs) have been recorded for the first time in Scotland. Northern Ireland enforced its first shellfish harvesting closure for high concentrations of domoic acid (the toxin responsible for amnesic shellfish poisoning, ASP) in 2012. A recent survey in Scottish waters (Regions 1, 6 and 7) has revealed the presence of domoic acid in the urine and faeces of harbour seals (Phoca vitulina). The impacts of these toxins on the health of marine mammals are unknown and a more detailed study is currently being undertaken. Many of the future impacts of climate change are unknown. Increasing sea surface temperatures as a result of climate change may increase the potential for blooms of species that are not currently found in UK and RoI waters through range expansion or human mediated introduction. There is evidence that no new HAB species have become established during the last two years. An increase in the duration of stratification of the water column may influence the abundance of HABs in UK and RoI waters. This is particularly relevant in shelf areas and Region 8, an area where offshore high biomass K. mikimotoi blooms have been hypothesized to initiate and impact coastal areas along the west of Ireland and Regions 6, 7 and 1. Conversely, an increase in wind speed and duration may reduce the duration of stratification in the water column. This may result in a decrease of some HAB dinoflagellate species and an increase in HAB diatom species. Little is known about the impacts of ocean acidification or changes in offshore circulation on the incidence of HABs. The role of offshore blooms in seeding coastal blooms (e.g. of K. mikimotoi) remains unknown and the lack of monitoring in Region 8 and on the shelf edge compounds this knowledge gap

    Perspectives of patients and healthcare professionals on mHealth for asthma self-management

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    Copyright ©ERS 2017. Mobile healthcare (mHealth) has the potential to revolutionise the self-management of long-term medical conditions such as asthma. A user-centred design is integral if mHealth is to be embraced by patients and healthcare professionals. The aim of this study was to determine the perspectives of individuals with asthma and healthcare professionals on the use of mHealth for asthma self-management. We used a sequential exploratory mixed methods design; focus groups informed the development of questionnaires, which were disseminated to individuals with asthma and healthcare professionals. Focus group participants (18 asthma patients and five healthcare professionals) identified 12 potential uses of mHealth. Questionnaire results showed that individuals with asthma (n=186) most frequently requested an mHealth system to monitor asthma over time (72%) and to collect data to present to healthcare teams (70%). In contrast, healthcare professionals (n=63) most frequently selected a system alerting patients to deteriorating asthma control (86%) and advising them when to seek medical attention (87%). Individuals with asthma were less likely than healthcare professionals (p < 0.001) to believe that assessing medication adherence and inhaler technique could improve asthma control. Our data provide strong support for mHealth for asthma self-management, but highlight fundamental differences between the perspectives of patients and healthcare professionals

    Search for Nova Presolar Grains: γ -Ray Spectroscopy of Ar 34 and its Relevance for the Astrophysical Cl 33 (p,γ) Reaction

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    The discovery of presolar grains in primitive meteorites has initiated a new era of research in the study of stellar nucleosynthesis. However, the accurate classification of presolar grains as being of specific stellar origins is particularly challenging. Recently, it has been suggested that sulfur isotopic abundances may hold the key to definitively identifying presolar grains with being of nova origins and, in this regard, the astrophysical Cl33(p,γ)Ar34 reaction is expected to play a decisive role. As such, we have performed a detailed γ-ray spectroscopy study of Ar34. Excitation energies have been measured with high precision and spin-parity assignments for resonant states, located above the proton threshold in Ar34, have been made for the first time. Uncertainties in the Cl33(p,γ) reaction have been dramatically reduced and the results indicate that a newly identified ℓ =0 resonance at Er=396.9(13) keV dominates the entire rate for T=0.25-0.40 GK. Furthermore, nova hydrodynamic simulations based on the present work indicate an ejected S32/S33 abundance ratio distinctive from type-II supernovae and potentially compatible with recent measurements of a presolar grain

    Level structure of the Tz=-1 nucleus Ar 34 and its relevance for nucleosynthesis in ONe novae

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    The Mg24+C12 fusion reaction was used to perform a detailed γ-ray spectroscopy study of the astrophysically important nucleus Ar34. In particular, an experimental setup, coupling the advanced γ-ray tracking array GRETINA with the well-established Argonne fragment mass analyzer (FMA), was employed to obtain excitation energies and spin-parity assignments for excited states in Ar34, both above and below the proton separation energy. For the first time, an angular distribution analysis of in-beam γ rays from fusion-evaporation reactions, using a tracking array, has been performed and Coulomb energy differences of analog states in the T=1, A=34 mirror system, explored from 0 to 6 MeV. Furthermore, we present a comprehensive discussion of the astrophysical Cl33(p,γ) stellar reaction rate, together with implications for the identification of nova presolar grains from sulfur isotopic abundances

    Confirmation of a new resonance in 26Si and contribution of classical novae to the galactic abundance of 26Al

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    © 2023 The Author(s). Published by the American Physical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/The 25Al(p ,γ ) reaction has long been highlighted as a possible means to bypass the production of 26Al cosmic γ rays in classical nova explosions. However, uncertainties in the properties of key resonant states in 26Si have hindered our ability to accurately model the influence of this reaction in such environments. We report on a detailed γ -ray spectroscopy study of 26Si and present evidence for the existence of a new, likely ℓ =1 , resonance in the 25Al + p system at Er=153.9 (15 ) keV. This state is now expected to provide the dominant contribution to the 25Al(p ,γ ) stellar reaction rate over the temperature range, T ≈0.1 −0.2 GK. Despite a significant increase in the rate at low temperatures, we find that the final ejected abundance of 26Al from classical novae remains largely unaffected even if the reaction rate is artificially increased by a factor of 10. Based on new, galactic chemical evolution calculations, we estimate that the maximum contribution of novae to the observed galactic abundance of 26Al is ≈0.2 M⊙ . Finally, we briefly highlight the important role that super-asymptotic giant branch stars may play in the production of 26Al.Peer reviewe

    Identification of polymorphic inversions from genotypes

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    Background: Polymorphic inversions are a source of genetic variability with a direct impact on recombination frequencies. Given the difficulty of their experimental study, computational methods have been developed to infer their existence in a large number of individuals using genome-wide data of nucleotide variation. Methods based on haplotype tagging of known inversions attempt to classify individuals as having a normal or inverted allele. Other methods that measure differences between linkage disequilibrium attempt to identify regions with inversions but unable to classify subjects accurately, an essential requirement for association studies. Results: We present a novel method to both identify polymorphic inversions from genome-wide genotype data and classify individuals as containing a normal or inverted allele. Our method, a generalization of a published method for haplotype data [1], utilizes linkage between groups of SNPs to partition a set of individuals into normal and inverted subpopulations. We employ a sliding window scan to identify regions likely to have an inversion, and accumulation of evidence from neighboring SNPs is used to accurately determine the inversion status of each subject. Further, our approach detects inversions directly from genotype data, thus increasing its usability to current genome-wide association studies (GWAS). Conclusions: We demonstrate the accuracy of our method to detect inversions and classify individuals on principled-simulated genotypes, produced by the evolution of an inversion event within a coalescent model [2]. We applied our method to real genotype data from HapMap Phase III to characterize the inversion status of two known inversions within the regions 17q21 and 8p23 across 1184 individuals. Finally, we scan the full genomes of the European Origin (CEU) and Yoruba (YRI) HapMap samples. We find population-based evidence for 9 out of 15 well-established autosomic inversions, and for 52 regions previously predicted by independent experimental methods in ten (9+1) individuals [3,4]. We provide efficient implementations of both genotype and haplotype methods as a unified R package inveRsion

    Template bank for compact binary mergers in the fourth observing run of Advanced LIGO, Advanced Virgo, and KAGRA

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    Template banks containing gravitational wave (GW) waveforms are essential for matched-filtering GW search pipelines. We describe the generation method, the design, and validation of the template bank used by the GstLAL-based inspiral pipeline to analyze data from the fourth observing run of LIGO scientific, Virgo, and KAGRA collaboration. This paper presents a template bank containing 1.8×1061.8 \times 10^6 templates that include merging neutron star - neutron star, neutron star - black hole, and black hole - black hole systems up to a total mass of 400400 M⊙M_\odot. Motivated by observations, component masses below 33 M⊙M_\odot have dimensionless spins ranging between ±0.05\pm 0.05, while component masses between 33 to 200200 M⊙M_\odot have dimensionless spins ranging between ±0.99\pm 0.99, where we assume spin-aligned systems. The low-frequency cutoff is 1515 Hz. The templates are placed in the parameter space according to the metric via a binary tree approach which took O(10)\mathcal{O}\left(10\right) minutes when jobs were parallelized. The template bank generated with this method has a 98%98\% match or higher for 90%90\% of the injections, thus being as effective as the template placement method used for the previous observation runs. The volumes of the templates are computed prior to template placement and the nearby templates have similar volumes in the coordinate space, henceforth, enabling a more efficient and less biased implementation of population models. SVD sorting of the O4 template bank has been renewed to use post-Newtonian phase terms, which improved the computational efficiency of SVD by nearly 4∼54 \sim 5 times as compared to conventional SVD sorting schemes. Template banks and searches focusing on the sub-solar mass parameter space and intermediate-mass black hole parameter space are conducted separately
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