692 research outputs found
Enhancing ordering dynamics in solvent-annealed block-copolymer films by lithographic hard masks supports
We studied solvent-driven ordering dynamics of block copolymer films
supported by a densely cross-linked polymer network designed as organic hard
mask (HM) for lithographic fabrications. The ordering of microphase separated
domains at low degrees of swelling corresponding to intermediate/strong
segregation regimes was found to proceed significantly faster in films on a HM
layer as compared to similar block copolymer films on silicon wafers. The
ten-fold enhancement of the chain mobility was evident in the dynamics of
morphological phase transitions and of related process of terrace-formation on
a macroscale, as well as in the degree of long-range lateral order of
nanostructures. The effect is independent of the chemical structure and on the
volume composition (cylinder-/ lamella-forming) of the block copolymers.
In-situ ellipsometric measurements of the swelling behavior revealed a
cumulative increase in 1-3 vol. % in solvent up-take by HM-block copolymer
bilayer films, so that we suggest other than dilution effect reasons for the
observed significant enhancement of the chain mobility in concentrated block
copolymer solutions. Another beneficial effect of the HM-support is the
suppression of the film dewetting which holds true even for low molecular
weight homopolymer polystyrene films at high degrees of swelling. Apart from
immediate technological impact in block copolymer-assisted nanolithography, our
findings convey novel insight into effects of molecular architecture on
polymer-solvent interactions.Comment: This document is the unedited Author's version of a Submitted Work
that was subsequently accepted for publication in Macromolecules, copyright
\c{opyright} American Chemical Society after peer review. To access the final
edited and published work see http://pubs.acs.org/doi/abs/10.1021/ma500561
Primordia initiation of mushroom (Agaricus bisporus) strains on axenic casing materials
The mushroom (Agaricus bisporus) has a
requirement for a ‘‘casing layer’’ that has specific
physical, chemical and microbiological properties
which stimulate and promote the initiation of primordia.
Some of these primordia then may develop
further into sporophores, involving differentiation of
tissue. Wild and commercial strains of A. bisporus
were cultured in axenic and nonaxenic microcosms,
using a rye grain substrate covered by a range of organic
and inorganic casing materials. In axenic culture,
A. bisporus (commercial strain A15) was capable
of producing primordia and mature sporophores on
charcoal (wood and activated), anthracite coal, lignite
and zeolite, but not on bark, coir, peat, rockwool,
silica or vermiculite. Of six strains tested, only
the developmental variant mutant, B430, produced
rudimentary primordia on axenic peat-based casing
material. However, none of these rudimentary primordia
developed differentiated tissues or beyond 4
mm diameter, either on axenic casing material in the
microcosms or in larger-scale culture. In larger-scale,
nonaxenic culture, strain B430 produced severely
malformed but mature sporophores in similar numbers
to those of other strains. Typically, 3–6% of primordia
developed into mature sporophores, but significant
differences in this proportion, as well as in
the numbers of primordia produced, were recorded
between 12 A. bisporus strains
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Inequality, exclusion and infant mortality: listening to bereaved mothers
yesThis chapter will examine issues of social justice by focussing on social exclusion and infant mortality. Infant mortality is defined as the death of a live born child before its first birthday. Social exclusion and infant mortality are both important areas of policy debate in the UK and globally (1).We will examine how far they are linked and will focus on ethnic minority populations with higher than average rates of infant mortality. The chapter continues by considering a small group of women who have experienced the death of an infant and who have come together in a group called HOPE. We ask how their experience might inform our understanding of the needs of women at the time of childbirth and in the weeks immediately following it. Their experiences illuminate how feelings of exclusion, and injustice, can be manifest in and through the structures and processes of engaging with health care professionals. The potential to promote social justice and enhance inclusion via listening to the voices of those who have had this experience of loss is considere
Heritage and national identity in post-socialist Albania
In this thesis I critically evaluate the concept of the “democratisation of memory” (Atkinson 2008) and to analyse the relationship between the “democratisation of memory” and the (re)construction of national identity through an analysis of changing practices of the (re)construction and consumption of three selected “myths” of Albanian national identity at heritage sites and museums. The three selected myths are; the myth of Illyrian-Albanian continuity, which is the origin myth of the Albanian nation; the myth of the Albanian national hero Skanderbeg; and myth and memory of the Stalinist dictator Enver Hoxha and of state-socialism. I will argue throughout this thesis that the particular “democratisation of memory” described by Atkinson (2008) is just one type or pattern of that phenomenon, and that different types or patterns of the “democratisation of memory” can occur in different contexts and in relation to different narratives, myths and memories. I will also argue that the relationship between the “democratisation of memory” and the (re)construction of national identity observed and analysed in Albania is quite different to that which Atkinson’s (2008) writings suggest. While Atkinson (2008) dwells on the way in which the “democratisation of memory” can allow “traditional” and “official” narratives to be challenged and undermined my research reveals that, in the context of post-socialist Albania, some “traditional” and “official” narratives of Albanian national identity – the myth of Illyrian-Albanian continuity and the myth of Skanderbeg - have actually been bolstered by the “democratisation of memory” as they are represented and consumed in more ways and by more individuals than before and are thereby more deeply embedded in everyday life. At the same time, though, my research shows that negative “official” post-socialist era representations of state-socialism have been challenged and undermined through the “democratisation of memory”. I therefor offer an expanded notion of the “democratisation of memory” based upon the post-socialist and Albanian contexts
Development and characterisation of a decellularised bovine osteochondral biomaterial for cartilage repair.
It is proposed that an acellular natural osteochondral scaffold will provide a successful repair material for the early intervention treatment of cartilage lesions, to prevent or slow the progression of cartilage deterioration to osteoarthritis. Here, we investigated the efficacy of methods for the decellularisation of bovine osteochondral plugs. The plugs were subject to four freeze/thaw cycles followed by two cycles of washes in hypotonic solution and low concentration (0.1 % w/v) sodium dodecyl sulphate with protease inhibitors. Plugs were treated with nuclease (DNase and RNase) treatment followed by sterilization in peracetic acid. Full tissue decellularisation was achieved as confirmed by histological analysis and DNA quantification, however the resultant acellular matrix had reduced glycosaminoglycan content which led to an increased percent deformation of cartilage. Furthermore, the acellular scaffold was not reproducibly biocompatible. Additional terminal washes were included in the process to improve biocompatibility, however, this led to visible structural damage to the cartilage. This damage was found to be minimised by reducing the cut edge to cartilage area ratio through decellularisation of larger cuts of osteochondral tissue
The discursive hegemony of Trump’s Jacksonian populism: Race, class, and gender in constructions and contestations of US national identity, 2016–2018
Contributing to burgeoning studies of populism, this article conceptualises and contextualises Trump’s language as ‘Jacksonian populism’. We explore how this style of populist discourse influenced political debates before and after Trump’s election. Ours is the first article to analyse opposition and media responses to Trump’s construction of ‘real America’ as that of a Jacksonian, White, and male working class. To do so, the article analyses 1165 texts, from the government, opposition, newspapers, television coverage, and social media. In addition to locating Trump’s reification of a mythologised White working class within a broader Jacksonian tradition, we find that the Democratic opposition and mainstream media initially reproduced this construction, furthering Trump’s cause. Even where discursive challenges were subsequently developed, they often served to reproduce a distinct – and hitherto unspoken for – White (male) working-class America. In short, early resistance actively reinforced Trump’s discursive hegemony, which centred on reclaiming the primacy of working, White America in the national identity
Impact of Thermal Maturation of the Upper Cretaceous Bituminous Limestone of Attarat Um Ghudran Central Jordan on Calcareous Nannofossil Preservation
Oil shale deposits of the Late Cretaceous from three boreholes in central Jordan were examined to assess the impact of thermal maturation on the content of nannofossils. Thermal activity has been shown to have a strong effect on organic matter content and composition but its effect on calcareous nannofossil assemblages remains inconclusive. This study aims to determine the impact of thermal maturation on nannofossil assemblages and to compare this to an estimated maturity level based on bulk geochemical analysis. Micropaleontological and geochemical analyses were conducted on 31 samples from three oil shale wells drilled in Attarat Um Ghudran central Jordan. Several types of nannofossil preservation have been recorded, including dissolution, overgrowth, and breakage. In the Jordan oil shale sections, nannofossils exhibit a variety of preservation types, with intense dissolution in the middle part of the study sections. The vast majority of the samples had high TOC enrichment, with 29 samples exceeding values of \u3e10%. Kerogen recovery and quality from the oil shale are very good, with a predominance of fluorescent amorphous organic matter (AOM) and minor algal components. The low fluorescence preservation index (FPI), which is 1 in most of the samples, indicates that alteration occurred due to intense thermal activities in the study interval. The palynomorph and AOM fluorescence, ranging from a spore coloration index (SCI) of 3 to 5, suggest that the studied samples were approaching the oil window. A correlation between the nannofossil preservation and geochemical parameters shows a predominance of poorly preserved nannofossils along with high total organic carbon contents and an elevated hydrogen index (HI). We show that low FPI values and a higher level of maturity are associated with poor nannofossil preservation, suggesting that nannofossils, in conjunction with petrographic analysis of kerogen, could be used as a rapid screening technique for estimating levels of oil-shale maturity. The nature of the tectonism in the study area, including faulting and a metamorphosed zone, enhanced the maturity, which might explain why the nannofossils were so significantly affected
Manipulation of body fat composition with sterculic acid can inhibit mammary carcinomas in vivo.
Sterculic acid, a delta-9-desaturase inhibitor, administered to rats caused a rise in the stearic:oleic acid ratio of total lipids in peripheral red cells, serum and liver (P less than 0.001). As a reduction in the stearic:oleic acid ratio has been described in cancer cells, we investigated the effect of sterculic acid on tumour growth. Female F344 rats were injected subcutaneously with two different doses of sterculic acid for 4 weeks prior to, and 4 weeks following, implantation of a nitrosomethylurea-induced mammary tumour. Tumour growth was inhibited equally by the two doses of sterculic acid (P less than 0.001). A rise in the stearic:oleic acid ratio of tumours was observed in rats treated for only 16 days with sterculic acid. Manipulation of the tissue stearic:oleic acid ratio inhibits transplanted mammary tumour growth in rats
Using drones to reveal the distribution and population abundance of threatened dasyatid rays at a nursery site in Seychelles
Drones are becoming increasingly valuable tools for studying species in marine environments. Here, a consumer-grade drone was used to elucidate the distribution and population abundance of two threatened dasyatid rays, Pastinachus ater and Urogymnus granulatus, in a remote marine protected area in the Republic of Seychelles. Over six weeks in March and April 2023, a total of 80 survey flights, covering an area of 3.2 km2, recorded 1262 P. ater and 822 U. granulatus. Findings revealed previously unresolved high-use areas for both species, which almost exclusively used sandy areas within the habitat and were found in greater abundances in areas closer to the shoreline. Spatial patterns in abundance were strongly correlated between species, with both often found in mixed-species groups. The site was shown to support large populations of both species with total population abundance estimates of 2524 (2029–3019 95% CI, 0.1 CV) for P. ater and 2136 (1732–2539 95% CI, 0.09 CV) for U. granulatus. This study highlights the applicability of drones in acquiring highly useful data for delineating critical habitats and informing the adaptive management of marine protected areas
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