787 research outputs found

    Combination of surgical excision and custom designed silicon pressure splint therapy for keloids on the helical rim

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    Keloids are defined as dermal fibrotic lesions which are considered an aberration of the wound healing process. Their etiology and pathogenesis are poorly understood. Different treatment modalities are described in the literature depending on the morphology and size of the keloid. We report a case of a large ear keloid on the helical rim which was successfully treated with surgery and a custom designed silicon pressure clip

    Vanadyl sulfate inhibits NO production via threonine phosphorylation of eNOS.

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    Exposure to excessive vanadium occurs in some occupations and with consumption of some dietary regimens for weight reduction and body building. Because vanadium is vasoactive, individuals exposed to excessive vanadium may develop adverse vascular effects. We have previously shown that vanadyl sulfate causes acute pulmonary vasoconstriction, which could be attributed in part to inhibition of nitric oxide production. In the present study we investigated whether NO inhibition was related to phosphorylation of endothelial nitric oxide synthase (eNOS). VOSO4 produced dose-dependent constriction of pulmonary arteries in isolated perfused lungs and pulmonary arterial rings and a right shift of the acetylcholine-dependent vasorelaxation curve. VOSO4 inhibited constitutive as well as A23187-stimulated NO production. Constitutive NO inhibition was accompanied by increased Thr495 (threonine at codon 495) phosphorylation of eNOS, which would inhibit eNOS activity. Thr495 phosphorylation of eNOS and inhibition of NO were partially reversed by pretreatment with calphostin C, a protein kinase C (PKC) inhibitor. There were no changes in Ser1177 (serine at codon 1177) or tyrosine phosphorylation of eNOS. These results indicate that VOSO4 induced acute pulmonary vasoconstriction that was mediated in part by the inhibition of endothelial NO production via PKC-dependent phosphorylation of Thr495 of eNOS. Exposure to excessive vanadium may contribute to pulmonary vascular diseases

    The California-Kepler survey. X. The radius gap as a function of stellar mass, metallicity, and age

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    In 2017, the California-Kepler Survey (CKS) published its first data release (DR1) of high-resolution optical spectra of 1305 planet hosts. Refined CKS planet radii revealed that small planets are bifurcated into two distinct populations, super-Earths (smaller than 1.5 R⊕) and sub-Neptunes (between 2.0 and 4.0 R⊕), with few planets in between (the "radius gap"). Several theoretical models of the radius gap predict variation with stellar mass, but testing these predictions is challenging with CKS DR1 due to its limited M⋆ range of 0.8–1.4 M⊙. Here we present CKS DR2 with 411 additional spectra and derived properties focusing on stars of 0.5–0.8 M⊙. We found that the radius gap follows Rp ∝ Pm with m = −0.10 ± 0.03, consistent with predictions of X-ray and ultraviolet- and core-powered mass-loss mechanisms. We found no evidence that m varies with M⋆. We observed a correlation between the average sub-Neptune size and M⋆. Over 0.5–1.4 M⊙, the average sub-Neptune grows from 2.1 to 2.6 R⊕, following RpMα{R}_{p}\propto {M}_{\star }^{\alpha } with α = 0.25 ± 0.03. In contrast, there is no detectable change for super-Earths. These M⋆–Rp trends suggest that protoplanetary disks can efficiently produce cores up to a threshold mass of Mc, which grows linearly with stellar mass according to Mc ≈ 10 M⊕(M⋆/M⊙). There is no significant correlation between sub-Neptune size and stellar metallicity (over −0.5 to +0.5 dex), suggesting a weak relationship between planet envelope opacity and stellar metallicity. Finally, there is no significant variation in sub-Neptune size with stellar age (over 1–10 Gyr), which suggests that the majority of envelope contraction concludes after ∼1 Gyr

    Expanding the parameters of academia

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    This paper draws on qualitative data gathered from two studies funded by the UK Leadership Foundation for Higher Education to examine the expansion of academic identities in higher education. It builds on Whitchurch’s earlier work, which focused primarily on professional staff, to suggest that the emergence of broadly based projects such as widening participation, learning support and community partnership is also impacting on academic identities. Thus, academic as well as professional staff are increasingly likely to work in multi-professional teams across a variety of constituencies, as well as with external partners, and the binary distinction between ‘academic’ and ‘non-academic’ roles and activities is no longer clear-cut. Moreover, there is evidence from the studies of an intentionality about deviations from mainstream academic career routes among respondents who could have gone either way. Consideration is therefore given to factors that influence individuals to work in more project-oriented areas, as well as to variables that affect ways in which these roles and identities develop. Finally, three models of academically oriented project activity are identified, and the implications of an expansion of academic identities are reviewed

    Predicting consumer biomass, size-structure, production, catch potential, responses to fishing and associated uncertainties in the world's marine ecosystems

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    Existing estimates of fish and consumer biomass in the world’s oceans are disparate. This creates uncertainty about the roles of fish and other consumers in biogeochemical cycles and ecosystem processes, the extent of human and environmental impacts and fishery potential. We develop and use a size-based macroecological model to assess the effects of parameter uncertainty on predicted consumer biomass, production and distribution. Resulting uncertainty is large (e.g. median global biomass 4.9 billion tonnes for consumers weighing 1 g to 1000 kg; 50% uncertainty intervals of 2 to 10.4 billion tonnes; 90% uncertainty intervals of 0.3 to 26.1 billion tonnes) and driven primarily by uncertainty in trophic transfer efficiency and its relationship with predator-prey body mass ratios. Even the upper uncertainty intervals for global predictions of consumer biomass demonstrate the remarkable scarcity of marine consumers, with less than one part in 30 million by volume of the global oceans comprising tissue of macroscopic animals. Thus the apparently high densities of marine life seen in surface and coastal waters and frequently visited abundance hotspots will likely give many in society a false impression of the abundance of marine animals. Unexploited baseline biomass predictions from the simple macroecological model were used to calibrate a more complex size- and trait-based model to estimate fisheries yield and impacts. Yields are highly dependent on baseline biomass and fisheries selectivity. Predicted global sustainable fisheries yield increases ≈4 fold when smaller individuals (< 20 cm from species of maximum mass < 1kg) are targeted in all oceans, but the predicted yields would rarely be accessible in practice and this fishing strategy leads to the collapse of larger species if fishing mortality rates on different size classes cannot be decoupled. Our analyses show that models with minimal parameter demands that are based on a few established ecological principles can support equitable analysis and comparison of diverse ecosystems. The analyses provide insights into the effects of parameter uncertainty on global biomass and production estimates, which have yet to be achieved with complex models, and will therefore help to highlight priorities for future research and data collection. However, the focus on simple model structures and global processes means that non-phytoplankton primary production and several groups, structures and processes of ecological and conservation interest are not represented. Consequently, our simple models become increasingly less useful than more complex alternatives when addressing questions about food web structure and function, biodiversity, resilience and human impacts at smaller scales and for areas closer to coasts

    Correlation in chicken between the marker LEI0258 alleles and Major Histocompatibility Complex sequences

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    <p>Abstract</p> <p>Background</p> <p>The LEI0258 marker is located within the B region of the chicken Major Histocompatibility Complex (MHC), and is surprisingly well associated with serology. Therefore, the correlation between the LEI0258 alleles and the MHC class I and the class II alleles at the level of sequences is worth investigating in chickens. Here we describe to which extent the LEI0258 alleles are associated with alleles of classical class I genes and non-classical class II genes, in reference animals as well as local breeds with unknown MHC haplotypes.</p> <p>Methods</p> <p>For the class I region, in an exploratory project, we studied 10 animals from 3 breeds: Rhode Island Red, White Leghorn and Fayoumi chickens, by cloning and sequencing <it>B-F1</it> and <it>B-F2</it> cDNA from exon 1 to 3’UTR. For the class II region, we reconstructed haplotypes of the 8.8 kb genomic region encompassing three non-classical class II genes: <it>B-DMA</it>, <it>B-DMB1</it> and <it>B-DMB2</it>, for 146 animals from more than 50 breeds including wild species of jungle fowls.</p> <p>Results</p> <p>Overall we found that the LEI0258 marker genotypes gave good indications of the MHC haplotypes, and a very good predictions (>0.95) of the heterozygosity of an animal at the MHC locus.</p> <p>Conclusions</p> <p>Our results show that the LEI0258 alleles are strongly associated with haplotypes of classical class I genes and non-classical class II genes, unravelling the reasons why this marker is becoming the reference marker for MHC genotyping in chickens.</p

    The transformation of transport policy in Great Britain? 'New Realism' and New Labour's decade of displacement activity

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    In a 1999 paper, Goodwin announced ‘the transformation of transport policy in Great Britain’. His central point was that consensus was emerging among policy makers and academics based on earlier work including Transport: The New Realism, which rejected previous orthodoxy that the supply of road space could and should be continually expanded to match demand. Instead a combination of investment in public transport, walking and cycling opportunities and – crucially – demand management should form the basis of transport policy to address rising vehicle use and associated increases in congestion and pollution / carbon emissions. This thinking formed the basis of the 1997 Labour government’s ‘sustainable transport’ policy, but after 13 years in power ministers neither transformed policy nor tackled longstanding transport trends. Our main aim in this paper is to revisit the concept of New Realism and re-examine its potential utility as an agent of change in British transport policy. Notwithstanding the outcome of Labour’s approach to transport policy, we find that the central tenets of the New Realism remain robust and that the main barriers to change are related to broader political and governance issues which suppress radical policy innovation

    Key reaction components affect the kinetics and performance robustness of cell-free protein synthesis reactions

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    This is the final version. Available on open access from Elsevier via the DOI in this recordData statement: All data are available both in Source Data files associated with this publication, and at https://doi.org/10.25405/data.ncl.17041931Cell-free protein synthesis (CFPS) reactions have grown in popularity with particular interest in applications such as gene construct prototyping, biosensor technologies and the production of proteins with novel chemistry. Work has frequently focussed on optimising CFPS protocols for improving protein yield, reducing cost, or developing streamlined production protocols. Here we describe a statistical Design of Experiments analysis of 20 components of a popular CFPS reaction buffer. We simultaneously identify factors and factor interactions that impact on protein yield, rate of reaction, lag time and reaction longevity. This systematic experimental approach enables the creation of a statistical model capturing multiple behaviours of CFPS reactions in response to components and their interactions. We show that a novel reaction buffer outperforms the reference reaction by 400% and importantly reduces failures in CFPS across batches of cell lysates, strains of E. coli, and in the synthesis of different proteins. Detailed and quantitative understanding of how reaction components affect kinetic responses and robustness is imperative for future deployment of cell-free technologies.Engineering and Physical Sciences Research Council (EPSRC

    The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water

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    We use numerical simulation to examine the possibility of a reversible liquid-liquid transition in supercooled water and related systems. In particular, for two atomistic models of water, we have computed free energies as functions of multiple order parameters, where one is density and another distinguishes crystal from liquid. For a range of temperatures and pressures, separate free energy basins for liquid and crystal are found, conditions of phase coexistence between these phases are demonstrated, and time scales for equilibration are determined. We find that at no range of temperatures and pressures is there more than a single liquid basin, even at conditions where amorphous behavior is unstable with respect to the crystal. We find a similar result for a related model of silicon. This result excludes the possibility of the proposed liquid-liquid critical point for the models we have studied. Further, we argue that behaviors others have attributed to a liquid-liquid transition in water and related systems are in fact reflections of transitions between liquid and crystal

    Planetary population synthesis

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    In stellar astrophysics, the technique of population synthesis has been successfully used for several decades. For planets, it is in contrast still a young method which only became important in recent years because of the rapid increase of the number of known extrasolar planets, and the associated growth of statistical observational constraints. With planetary population synthesis, the theory of planet formation and evolution can be put to the test against these constraints. In this review of planetary population synthesis, we first briefly list key observational constraints. Then, the work flow in the method and its two main components are presented, namely global end-to-end models that predict planetary system properties directly from protoplanetary disk properties and probability distributions for these initial conditions. An overview of various population synthesis models in the literature is given. The sub-models for the physical processes considered in global models are described: the evolution of the protoplanetary disk, the planets' accretion of solids and gas, orbital migration, and N-body interactions among concurrently growing protoplanets. Next, typical population synthesis results are illustrated in the form of new syntheses obtained with the latest generation of the Bern model. Planetary formation tracks, the distribution of planets in the mass-distance and radius-distance plane, the planetary mass function, and the distributions of planetary radii, semimajor axes, and luminosities are shown, linked to underlying physical processes, and compared with their observational counterparts. We finish by highlighting the most important predictions made by population synthesis models and discuss the lessons learned from these predictions - both those later observationally confirmed and those rejected.Comment: 47 pages, 12 figures. Invited review accepted for publication in the 'Handbook of Exoplanets', planet formation section, section editor: Ralph Pudritz, Springer reference works, Juan Antonio Belmonte and Hans Deeg, Ed
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