3,855 research outputs found
Effects of Microstructure Formation on the Stability of Vapor Deposited Glasses
Glasses formed by physical vapor deposition (PVD) are an interesting new
class of materials, exhibiting properties thought to be equivalent to those of
glasses aged for thousands of years. Exerting control over the structure and
properties of PVD glasses formed with different types of glass-forming
molecules is now an emerging challenge. In this work, we study coarse grained
models of organic glass formers containing fluorocarbon tails of increasing
length, corresponding to an increased tendency to form microstructures. We use
simulated PVD to examine how the presence of the microphase separated domains
in the supercooled liquid influences the ability to form stable glasses. This
model suggests that increasing molecule tail length results in decreased
thermodynamic and kinetic stability of the molecules in PVD films. The reduced
stability is further linked to the reduced ability of these molecules to
equilibrate at the free surface during PVD. We find that as the tail length is
increased, the relaxation time near the surface of the supercooled equilibrium
liquid films of these molecules are slowed and become essentially bulk-like,
due to the segregation of the fluorocarbon tails to the free surface. Surface
diffusion is also markedly reduced due to clustering of the molecules at the
surface. Based on these results, we propose a trapping mechanism where tails
are unable to move between local phase separated domains on the relevant
deposition time scales
A Census Atlas of Irish Agriculture
End of Project ReportComputerised mapping systems were developed to analyse agricultural census statistics and
data from agricultural policy administration sources. The objective was to identify local
geographical variations in the structure and trends in the agricultural economy by mapping
the available information, principally at the level of the District Electoral Division (DED) and
the Rural District (RD). There were 3,113 DEDs and 156 RDs in the analysis. The main database was the 1991 Census of Agriculture, the latest available. Some statistics
are updated annually and where possible these were used in tabular form to trace the 1991-
1997 trends for Regional Authority areas. Conclusions: There are distinctive farming regions in the country whose boundaries span unevenly across
county limits. These are undergoing different processes of change depending on their
resource base, their responses to economic imperatives, and the policy environment.
• Commercial farming has become increasingly associated with areas south and east of a line
from Limerick to Dundalk.
• It is likely that policies and trends post 2000 will further increase the differences in resource
use between commercial farming and other areas
Nursing sensitive outcomes: identifying a definition, exploration of conceptual challenges and an overview of the literature
Introduction/background: A literature review on nursing sensitive outcomes has been conducted as part of a larger research project. The literature was reviewed to: - identify a definition of nursing sensitive outcomes - determine the conceptual models used to describe nursing sensitive outcomes - identify significant contributions made by researchers on the development and use of nursing sensitive outcomes in clinical practice.The overall aim of the research project is to develop a set of indicators that provides a balanced view of nursing care and its contribution to patient outcomes. It is anticipated that this research will broaden the debate on nursing sensitive outcomes so that the contribution that nursing care makes to patient outcomes is able to be identified and measured
Shifting Patterns of Nitrogen Excretion and Amino Acid Catabolism Capacity during the Life Cycle of the Sea Lamprey (\u3cem\u3ePetromyzon mariunus\u3c/em\u3e)
The jawless fish, the sea lamprey (Petromyzon marinus), spends part of its life as a burrow-dwelling, suspension-feeding larva (ammocoete) before undergoing a metamorphosis into a free swimming, parasitic juvenile that feeds on the blood of fishes. We predicted that animals in this juvenile, parasitic stage have a great capacity for catabolizing amino acids when large quantities of protein-rich blood are ingested. The sixfold to 20-fold greater ammonia excretion rates (JAmm) in postmetamorphic (nonfeeding) and parasitic lampreys compared with ammocoetes suggested that basal rates of amino acid catabolism increased following metamorphosis. This was likely due to a greater basal amino acid catabolizing capacity in which there was a sixfold higher hepatic glutamate dehydrogenase (GDH) activity in parasitic lampreys compared with ammocoetes. Immunoblotting also revealed that GDH quantity was 10-fold and threefold greater in parasitic lampreys than in ammocoetes and upstream migrant lampreys, respectively. Higher hepatic alanine and aspartate aminotransferase activities in the parasitic lampreys also suggested an enhanced amino acid catabolizing capacity in this life stage. In contrast to parasitic lampreys, the twofold larger free amino acid pool in the muscle of upstream migrant lampreys confirmed that this period of natural starvation is accompanied by a prominent proteolysis. Carbamoyl phosphate synthetase III was detected at low levels in the liver of parasitic and upstream migrant lampreys, but there was no evidence of extrahepatic (muscle, intestine) urea production via the ornithine urea cycle. However, detection of arginase activity and high concentrations of arginine in the liver at all life stages examined infers that arginine hydrolysis is an important source of urea. We conclude that metamorphosis is accompanied by a metabolic reorganization that increases the capacity of parasitic sea lampreys to catabolize intermittently large amino acid loads arising from the ingestion of protein rich blood from their prey/hosts. The subsequent generation of energy-rich carbon skeletons can then be oxidized or retained for glycogen and fatty acid synthesis, which are essential fuels for the upstream migratory and spawning phases of the sea lamprey’s life cycle
Disease activity flares and pain flares in an early rheumatoid arthritis inception cohort; characteristics, antecedents and sequelae
© 2019 The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: RA flares are common and disabling. They are described in terms of worsening inflammation but pain and inflammation are often discordant. To inform treatment decisions, we investigated whether inflammatory and pain flares are discrete entities. Methods: People from the Early RA Network (ERAN) cohort were assessed annually up to 11 years after presentation (n = 719, 3703 person-years of follow up). Flare events were defined in 2 different ways that were analysed in parallel; DAS28 or Pain Flares. DAS28 Flares satisfied OMERACT flare criteria of increases in DAS28 since the previous assessment (≥1.2 points if active RA or ≥ 0.6 points if inactive RA). A ≥ 4.8-point worsening of SF36-Bodily Pain score defined Pain Flares. The first documented episode of each of DAS28 and Pain Flare in each person was analysed. Subgroups within DAS28 and Pain Flares were determined using Latent Class Analysis. Clinical course was compared between flare subgroups. Results: DAS28 (45%) and Pain Flares (52%) were each common but usually discordant, with 60% of participants in DAS28 Flare not concurrently in Pain Flare, and 64% of those in Pain Flare not concurrently in DAS28 Flare. Three discrete DAS28 Flare subgroups were identified. One was characterised by increases in tender/swollen joint counts (14.4%), a second by increases in symptoms (13.1%), and a third displayed lower flare severity (72.5%). Two discrete Pain Flare subgroups were identified. One occurred following low disease activity and symptoms (88.6%), and the other occurred on the background of ongoing active disease and pain (11.4%). Despite the observed differences between DAS28 and Pain Flares, each was associated with increased disability which persisted beyond the flare episode. Conclusion: Flares are both common and heterogeneous in people with RA. Furthermore our findings indicate that for some patients there is a discordance between inflammation and pain in flare events. This discrete flare subgroups might reflect different underlying inflammation and pain mechanisms. Treatments addressing different mechanisms might be required to reduce persistent disability after DAS28 and Pain Flares.Peer reviewedFinal Published versio
A tunable amorphous p-type ternary oxide system: the highly mismatched alloy of copper tin oxide
The approach of combining two mismatched materials to form an amorphous alloy was used to synthesise ternary oxides of CuO and SnO2. These materials were analysed across a range of compositions, and the electronic structure was modelled using density functional theory. In contrast to the gradual reduction in optical band gap, the lms show a sharp reduction in both transparency and electrical resistivity with copper contents of greater than 50 %. Simulations indicate this change is caused by a transition from a dominant Sn
5s to Cu 3d contribution to the upper valence band. A corresponding decrease in energetic disorder results in increased charge percolation pathways: a `compositional mobility edge'. Contributions from Cu(II) sub band-gap states are responsible for the reduction in optical transparency
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Carbonate Deposits in Marine Fish Intestines: A New Source of Biomineralization
Marine teleostean fish are hypo-osmotic to seawater. As part of a multiorgan osmoregulatory strategy they drink seawater and selectively absorb water and minerals across the intestinal epithelium. Notably, divalent cations (Ca2+ and Mg2-) are left behind. We report here that in the gulf toadfish, Opsanus beta, the ionic by-products of osmoregulation in the intestine contribute to de novo formation of a carbonate mineral, tentatively identified as calcian kutnohorite. Our data suggest that intestinal mineralization is a general feature of osmoregulation in marine teleosts and that this process is an unrecognized and possibly substantial source of marine carbonate sediments
Discrete trajectories of resolving and persistent pain in people with rheumatoid arthritis despite undergoing treatment for inflammation: results from three UK cohorts
Rheumatoid arthritis (RA) is an example of human chronic inflammatory pain. Modern treatments suppress inflammation, yet pain remains a major problem for many people with RA. We hypothesised that discrete RA subgroups might display favourable or unfavourable pain trajectories when receiving treatment, and that baseline characteristics will predict trajectory allocation.Growth Mixture Modelling was used to identify discrete trajectories of SF36-Bodily Pain scores during 3 years in 3 RA cohorts (Early RA Network (ERAN); n=683, British Society for Rheumatology Biologics Register Biologics (n=7090) and Non-Biologics (n=1720) cohorts. Logistic regression compared baseline predictor variables between trajectories. The role of inflammation was examined in a subgroup analysis of people with normal levels of inflammatory markers after 3 years.Mean SF36-Bodily Pain scores in each cohort improved but remained throughout 3y follow up >1 SD worse than the UK general population average. Discrete Persistent Pain (59% to 79% of cohort participants) and Resolving Pain (19% to 27%) trajectories were identified in each cohort. In ERAN, a third trajectory displaying persistently Low Pain (23%) was also identified. In people with normal levels of inflammatory markers after 3 years, 65% of them were found to follow a Persistent Pain trajectory. When trajectories were compared, greater disability (aORs 2.3-2.5 per unit baseline Health Assessment Questionnaire score) and smoking history (aORs 1.6-1.8) were risk factors for Persistent Pain trajectories in each cohort.In conclusion, distinct trajectories indicate patient subgroups with very different pain prognosis during RA treatment. Inflammation does not fully explain the pain trajectories, and non-inflammatory factors as well as acute phase response predict which trajectory an individual will follow. Targeted treatments additional to those which suppress inflammation might reduce the long term burden of arthritis pain
The effect of heterospecific and conspecific competition on inter-individual differences in tungara frog tadpole (Engystomops pustulosus) behavior:Effect of competition on variation in tadpole behavior
Repeated social interactions with conspecifics and/or heterospecifics during early development may drive the differentiation of behavior among individuals. Competition is a major form of social interaction and its impacts can depend on whether interactions occur between conspecifics or heterospecifics and the directionality of a response could be specific to the ecological context that they are measured in. To test this, we reared tungara frog tadpoles (Engystomops pustulosus) either in isolation, with a conspecific tadpole or with an aggressive heterospecific tadpole, the whistling frog tadpole (Leptodactylus fuscus). In each treatment, we measured the body size and distance focal E. pustulosus tadpoles swam in familiar, novel and predator risk contexts six times during development. We used univariate and multivariate hierarchical mixed effect models to investigate the effect of treatment on mean behavior, variance among and within individuals, behavioral repeatability and covariance among individuals in their behavior between contexts. There was a strong effect of competition on behavior, with different population and individual level responses across social treatments. Within a familiar context, the variance in the distance swam within individuals decreased under conspecific competition but heterospecific competition caused more variance in the average distance swam among individuals. Behavioral responses were also context specific as conspecific competition caused an increase in the distance swam within individuals in novel and predator risk contexts. The results highlight that the impact of competition on among and within individual variance in behavior is dependent on both competitor species identity and context
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