4,237 research outputs found

    Commentary: Totally Tubular - Northern Science's Most Excellent Adventure

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    ... The second day of our meetings revisited [the] theme of northern science "going down the tubes." One of us, ... cautioned against too dim a view of the state of our interest. "While it's undeniable that northern science is going down the tubes, as my colleagues suggests," he said, "I think it is also important to realize that some of those tubes are directing us towards some pretty interesting places - increased interdisciplinary work and greater relevance to the northern community itself are two trends which the current funding levels are forcing us to consider as we seek to legitimate our proposed research. These are not, I think, such bad directions to see our activities descend to" .... My goal here ... is to discuss more fully some of the current trajectories of the journey of northern science and suggest that in thinking "tubular" about the trip we can find ourselves in a most excellent adventure. Northern research, primarily due to its geographic isolation and associated costs, has long relied on a multidisciplinary approach. ... The second feature of northern research that has been sustained to some degree over the years has been the extent to which local populations have been involved as critical participants in the research. In the early years of poor communications and logistical staging, native northerners often made the difference in the success or failure of a project - at times their guidance, food, habitations and local knowledge quite literally made a difference between life and death. As state intervention in the North increased, aboriginal people became more marginalized in their participation, but the symbiotic heritage remained. It is partly for this reason that the current recognition of the potential for traditional knowledge to contribute to scientific research has been taken most seriously in the North. ... A good many northern scientists look back on the 1960s and '70s as the halcyon days of northern research, a time when there was seemingly inexhaustible funding and access to logistical support. ... That the reports of public inquiries, along with a downturn in world petroleum prices, effectively ended the grand schemes of these interests and their associated research should demonstrate pretty clearly the relationship between science and the business community. This is a relationship that many of us assume without a second thought; why then the trepidation displayed at the prospect of greater involvement of wider local community interest in research? These are not just academic issues of informed debate for this journal and our conference libations; they are critical to the emergence of a legitimate indigenous northern scholarly tradition and that role that northern-oriented academics are going to play in it. ..

    The Influence of the effect of solute on the thermodynamic driving force on grain refinement of Al alloys

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    Grain refinement is known to be strongly affected by the solute in cast alloys. Addition of some solute can reduce grain size considerably while others have a limited effect. This is usually attributed to the constitutional supercooling which is quantified by the growth restriction factor, Q. However, one factor that has not been considered is whether different solutes have differing effects on the thermodynamic driving force for solidification. This paper reveals that addition of solute reduces the driving force for solidification for a given undercooling, and that for a particular Q value, it is reduced more substantially when adding eutectic-forming solutes than peritectic-forming elements. Therefore, compared with the eutectic-forming solutes, addition of peritectic-forming solutes into Al alloys not only possesses a higher initial nucleation rate resulted from the larger thermodynamic driving force for solidification, but also promotes nucleation within the constitutionally supercooled zone during growth. As subsequent nucleation can occur at smaller constitutional supercoolings for peritectic-forming elements, a smaller grain size is thus produced. The very small constitutional supercooling required to trigger subsequent nucleation in alloys containing Ti is considered as a major contributor to its extraordinary grain refining efficiency in cast Al alloys even without the deliberate addition of inoculants.The Australian Research Council (ARC DP10955737)

    Cloned defective interfering influenza RNA and a 7 possible pan-specific treatment of respiratory virus 8 diseases

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    Defective interfering (DI) genomes are characterised by their ability to interfere with the 3 replication of the virus from which they were derived and other genetically compatible 4 viruses. DI genomes are synthesized by nearly all known viruses and represent a vast 5 natural reservoir of antivirals that can potentially be exploited for use in the clinic. This review 6 describes the application of DI virus to protect from virus-associated diseases in vivo using 7 as an example a highly active cloned influenza A DI genome and virus that protects broadly 8 in preclinical trials against different subtypes of influenza A and against non-influenza A 9 respiratory viruses. This influenza A-derived DI genome protects by two totally different 10 mechanisms: molecular interference with influenza A replication and by stimulating innate 11 immunity that acts against non-influenza A viruses. The review considers what is needed to 12 develop DI genomes to the point of entry into clinical trials

    Cloned defective interfering influenza virus protects ferrets from pandemic 2009 influenza A virus and allows protective immunity to be established

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    Influenza A viruses are a major cause of morbidity and mortality in the human population, causing epidemics in the winter, and occasional worldwide pandemics. In addition there are periodic outbreaks in domestic poultry, horses, pigs, dogs, and cats. Infections of domestic birds can be fatal for the birds and their human contacts. Control in man operates through vaccines and antivirals, but both have their limitations. In the search for an alternative treatment we have focussed on defective interfering (DI) influenza A virus. Such a DI virus is superficially indistinguishable from a normal virus but has a large deletion in one of the eight RNAs that make up the viral genome. Antiviral activity resides in the deleted RNA. We have cloned one such highly active DI RNA derived from segment 1 (244 DI virus) and shown earlier that intranasal administration protects mice from lethal disease caused by a number of different influenza A viruses. A more cogent model of human influenza is the ferret. Here we found that intranasal treatment with a single dose of 2 or 0.2 µg 244 RNA delivered as A/PR/8/34 virus particles protected ferrets from disease caused by pandemic virus A/California/04/09 (A/Cal; H1N1). Specifically, 244 DI virus significantly reduced fever, weight loss, respiratory symptoms, and infectious load. 244 DI RNA, the active principle, was amplified in nasal washes following infection with A/Cal, consistent with its amelioration of clinical disease. Animals that were treated with 244 DI RNA cleared infectious and DI viruses without delay. Despite the attenuation of infection and disease by DI virus, ferrets formed high levels of A/Cal-specific serum haemagglutination-inhibiting antibodies and were solidly immune to rechallenge with A/Cal. Together with earlier data from mouse studies, we conclude that 244 DI virus is a highly effective antiviral with activity potentially against all influenza A subtypes

    Droplets Transport in a Microfluidic Chip for In Vitro Compartmentalisation

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    In vitro compartmentalisation is an emerging technology for protein evolution and selection. In this presentation, we will report the development of a microdrop-based microfluidic platform for in vitro enzyme evolution and selection applications. A microfluidic chip has been developed and fabricated using the standard photolithography method in conjunction with electroplating and hot embossing techniques. A cross channel geometry was used to focus liquid flows for droplet generation. To realize on-chip compartmentalised bio-reactions, two droplet generators were fabricated on the same chip. Experiments have been carried out to measure droplet size, generation rate and speed using a photographic technique. Droplet size was found to be decreasing with increasing focusing oil flow rate for a given aqueous phase flow rate. When two droplet generators are used in the same chip, the droplets may be generated asynchronously due to different flow conditions. If the droplets were significantly smaller than channel size, the faster moving droplets could pass the slower moving droplets with little coalescence. If the droplets were of the channel size, the faster moving droplets would break or fuse with the slow droplets. To achieve high rate of droplet fusion, active control should be in place for synchronous generation and fusion

    A 2.75-Approximation Algorithm for the Unconstrained Traveling Tournament Problem

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    A 2.75-approximation algorithm is proposed for the unconstrained traveling tournament problem, which is a variant of the traveling tournament problem. For the unconstrained traveling tournament problem, this is the first proposal of an approximation algorithm with a constant approximation ratio. In addition, the proposed algorithm yields a solution that meets both the no-repeater and mirrored constraints. Computational experiments show that the algorithm generates solutions of good quality.Comment: 12 pages, 1 figur

    Understanding the SARS-CoV-2 virus neutralizing antibody response : lessons to be learned from HIV and respiratory syncytial virus

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    The SARS-CoV-2 pandemic commenced in 2019 and is still ongoing. Neither infection nor vaccination give long-lasting immunity and, here, in an attempt to understand why this might be, we have compared the neutralizing antibody responses to SARS-CoV-2 with those specific for human immunodeficiency virus type 1 (HIV-1) and respiratory syncytial virus (RSV). Currently, most of the antibodies specific for the SARS-CoV-2 S protein map to three broad antigenic sites, all at the distal end of the S trimer (receptor-binding site (RBD), sub-RBD and N-terminal domain), whereas the structurally similar HIV-1 and the RSV F envelope proteins have six antigenic sites. Thus, there may be several antigenic sites on the S trimer that have not yet been identified. The epitope mapping, quantitation and longevity of the SARS-CoV-2 S-protein-specific antibodies produced in response to infection and those elicited by vaccination are now being reported for specific groups of individuals, but much remains to be determined about these aspects of the host–virus interaction. Finally, there is a concern that the SARS-CoV-2 field may be reprising the HIV-1 experience, which, for many years, used a virus for neutralization studies that did not reflect the neutralizability of wild-type HIV-1. For example, the widely used VSV-SARS-CoV-2-S protein pseudotype has 10-fold more S trimers per virion and a different configuration of the trimers compared with the SARS-CoV-2 wild-type virus. Clarity in these areas would help in advancing understanding and aid countermeasures of the SARS-CoV-2 pandemic

    'Word from the street' : when non-electoral representative claims meet electoral representation in the United Kingdom

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    Taking the specific case of street protests in the UK – the ‘word from the street’– this article examines recent (re)conceptualizations of political representation, most particularly Saward’s notion of ‘representative claim’. The specific example of nonelectoral claims articulated by protestors and demonstrators in the UK is used to illustrate: the processes of making, constituting, evaluating and accepting claims for and by constituencies and audiences; and the continuing distinctiveness of claims based upon electoral representation. Two basic questions structure the analysis: first, why would the political representative claims of elected representatives trump the nonelectoral claims of mass demonstrators and, second, in what ways does the ‘perceived legitimacy’ of the former differ from the latter

    Low dose influenza virus challenge in the ferret leads to increased virus shedding and greater sensitivity to oseltamivir

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    Ferrets are widely used to study human influenza virus infection. Their airway physiology and cell receptor distribution makes them ideal for the analysis of pathogenesis and virus transmission, and for testing the efficacy of anti-influenza interventions and vaccines. The 2009 pandemic influenza virus (H1N1pdm09) induces mild to moderate respiratory disease in infected ferrets, following inoculation with 106 plaque-forming units (pfu) of virus. We have demonstrated that reducing the challenge dose to 102 pfu delays the onset of clinical signs by 1 day, and results in a modest reduction in clinical signs, and a less rapid nasal cavity innate immune response. There was also a delay in virus production in the upper respiratory tract, this was up to 9-fold greater and virus shedding was prolonged. Progression of infection to the lower respiratory tract was not noticeably delayed by the reduction in virus challenge. A dose of 104 pfu gave an infection that was intermediate between those of the 106 pfu and 102 pfu doses. To address the hypothesis that using a more authentic low challenge dose would facilitate a more sensitive model for antiviral efficacy, we used the well-known neuraminidase inhibitor, oseltamivir. Oseltamivir-treated and untreated ferrets were challenged with high (106 pfu) and low (102 pfu) doses of influenza H1N1pdm09 virus. The low dose treated ferrets showed significant delays in innate immune response and virus shedding, delayed onset of pathological changes in the nasal cavity, and reduced pathological changes and viral RNA load in the lung, relative to untreated ferrets. Importantly, these observations were not seen in treated animals when the high dose challenge was used. In summary, low dose challenge gives a disease that more closely parallels the disease parameters of human influenza infection, and provides an improved pre-clinical model for the assessment of influenza therapeutics, and potentially, influenza vaccines
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