68 research outputs found

    High major histocompatibility complex class I polymorphism despite bottlenecks in wild and domesticated populations of the zebra finch ()

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    Background Two subspecies of zebra finch, Taeniopygia guttata castanotis and T. g. guttata are native to Australia and the Lesser Sunda Islands, respectively. The Australian subspecies has been domesticated and is now an important model system for research. Both the Lesser Sundan subspecies and domesticated Australian zebra finches have undergone population bottlenecks in their history, and previous analyses using neutral markers have reported reduced neutral genetic diversity in these populations. Here we characterize patterns of variation in the third exon of the highly variable major histocompatibility complex (MHC) class I α chain. As a benchmark for neutral divergence, we also report the first mitochondrial NADH dehydrogenase 2 (ND2) sequences in this important model system. Results Despite natural and human-mediated population bottlenecks, we find that high MHC class I polymorphism persists across all populations. As expected, we find higher levels of nucleotide diversity in the MHC locus relative to neutral loci, and strong evidence of positive selection acting on important residues forming the peptide-binding region (PBR). Clear population differentiation of MHC allele frequencies is also evident, and this may be due to adaptation to new habitats and associated pathogens and/or genetic drift. Whereas the MHC Class I locus shows broad haplotype sharing across populations, ND2 is the first locus surveyed to date to show reciprocal monophyly of the two subspecies. Conclusions Despite genetic bottlenecks and genetic drift, all surveyed zebra finch populations have maintained high MHC Class I diversity. The diversity at the MHC Class I locus in the Lesser Sundan subspecies contrasts sharply with the lack of diversity in previously examined neutral loci, and may thus be a result of selection acting to maintain polymorphism. Given uncertainty in historical population demography, however, it is difficult to rule out neutral processes in maintaining the observed diversity. The surveyed populations also differ in MHC Class I allele frequencies, and future studies are needed to assess whether these changes result in functional immune differences

    A novel approach of introducing crystalline protection material and curing agent in fresh concrete for enhancing hydrophobicity

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    A new line of research to enhance the performance of concrete under adverse (harsh) and normal (air cured) curing conditions is presented. A crystallising hydrophobic admixture and curing agents were added to fresh concrete to improve its resistance against severe environmental conditions. A two-stage approach was pursued by adding the crystallising admixture to fresh concrete followed by curing agents, in a wax and liquid forms, in a separate application process, followed by exposing concrete to normal and adverse curing conditions. Results obtained suggests that protecting concrete with the crystallising admixture followed by applying wax based curing agent improves concrete strength and its resistance to water ingress than concrete cured with the liquid curing agent. When following the crystallising-wax treating system under adverse curing conditions, a more conserved strength was noticed compared to that produced by the crystallising-liquid system. Using the liquid curing agent in concrete with high water to cement ratio (w/c) has increased the cracks in the internal structure, while water permeability has decreased, either under normal curing conditions or adverse conditions. Following this protection-curing system in industry would resolve the problem of applying protection on wet surfaces and increase concrete’s resistance to deterioration. A microscopic study of the crystallising material was attained with a Scanning Electron Microscope (SEM) to check crystal growth with time

    Innovative Business Approaches for the Reduction of Extreme Poverty and Marginality?

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    Extreme poverty is an immense political and market failure, wasting the potential of hundreds of millions of people. Investing in the creation of markets that include the extreme poor and marginalized should thus not only be considered as a charitable activity, but promises high returns on investments - in financial and humanitarian terms. However, while the potential of innovative business approaches to target the poor that live close to the poverty line is increasingly being recognised, the question remains how far these approaches can push the margin to also include those that are extremely poor. And how can those that are marginalized from development opportunities be brought into and benefit from market-based systems to improve the quality of their lives? The impressive rise of business approaches to combating poverty stems from a long history of debates on the role of businesses in society. From an initial focus on social objectives as an external add-on, leading business thinkers have increasingly been stressing the benefits for companies of integrating social considerations into their core business strategies, for instance by targeting lowincome consumers (or 'bottom of the pyramid' markets) or strengthening supply and distribution chains through the involvement of local communities as part of inclusive business strategies. Others - most notably Muhammed Yunus along with other social entrepreneurs - are taking this argument one step further, advocating the use of business strategies primarily to address social goals rather than for financial gains. Thus, in discussions on the role of business in society, profit maximisation as the primary objective of business operations is increasingly making way for business initiatives that are guided by social objectives. This trend is also being supported by growing interest among investors in financing enterprises that promote social or environmental objectives, either as their primary aim or in parallel with seeking to generate financial returns. How suitable these different approaches are to engage the poorest and marginalized depends in part on the extent to which they are able to involve the extreme poor themselves, their flexibility to direct business objectives towards the reduction of extreme poverty and marginality, and their ability to successfully operate with non-business public and civil society partners and in sectors of particular interest to the extreme poor. Further research and action is needed to identify outcome-focused indicators and measurement tools for social value creation, examine possible government measures to support business activities for the poorest, and consider complementarities between the different business approaches. While we recognise that it is unrealistic to expect businesses to be able to reach all of the extreme poor, we believe that the boundaries of innovative business operations can be pushed much further to include a far larger number of the poorest and marginalized

    Leveraging neuroscience education to address stigma related to opioid use disorder in the community: a pilot study

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    Opioid use disorder (OUD) and overdose deaths are a public health crisis. One contributing factor is stigma towards people who use opioids. We developed and conducted a public-facing, half-day educational event designed to challenge misperceptions about OUD from a contemporary neuroscience perspective. Participants engaged with three different resources on the neurobiology of addiction, and, at the end of the event, they rated its effectiveness. We also collected and compared pre- and post-event composite OUD stigma scales. Participants rated our approach and the overall event as highly effective. Additionally, OUD stigma scores were lower immediately following the event, and this decrease was primarily driven by decreased internalized stigma. Here, we demonstrate an effective proof-of-concept that an accessible, public-facing, neuroscience education event may reduce OUD stigma in the community

    SOLITARY BRONCHIAL POLYPS OF INFLAMMATORY ORIGIN

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    Underground ventilated wall based on TRC blocks

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    Abstract Ventilated wall is an air-insulating method, which principle is to create a ventilated cavity along the surface of remediated underground wall (usually masonry). The paper describes an innovative solution of this remediation method based on the precast blocks made form textile-reinforced concrete - TRC. The main advantages of the solution (compared to traditional constructions - masonry, hollow bricks filled by cement mortar, monolithic concrete) are low labour difficulty, fast montage and high durability. Since the blocks are not structurally connected or anchored to remediated structure, it is a non-invasive method, which is also suitable for installation in historically valuable buildings. The technical solution is protected by patent CZ307501(B6).</jats:p
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