4,592 research outputs found

    PPC Update

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    PPC Update

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    PPC Update

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    Creating Fictitious Family Memories: The Closed Stranger Adoption of Māori Children into White Families

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    Between 1955 and 1985 approximately 45,000 closed stranger adoptions took place in Aotearoa New Zealand. Many of these adoptions involved children of Māori ancestry, who were placed into white families, where links to their whakapapa were severed and a space for fictitious narratives (including memories) was created. This article reveals some adoption fictions experienced in the lives of six Māori people who were adopted into Pākehā families. Using a Māori-centred research approach, it found that there were common fictions that Māori adopted people navigated, through counter-narratives and narratives of repair, in their quest to create their own identity

    Comparative Analysis Of Zebrafish And Planarian Model Systems For Developmental Neurotoxicity Screens Using An 87-Compound Library

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    There is a clear need to establish and validate new methodologies to more quickly and efficiently screen chemicals for potential toxic effects, particularly on development. The emergence of alternative animal systems for rapid toxicology screens presents valuable opportunities to evaluate how systems complement each other. In this article, we compare a chemical library of 87-compounds in two such systems, developing zebrafish and freshwater planarians, by screening for developmental neurotoxic effects. We show that the systems’ toxicological profiles are complementary to each other, with zebrafish yielding more detailed morphological endpoints and planarians more behavioral endpoints. Overall, zebrafish was more sensitive to this chemical library, yielding 86/87 hits, compared to 50/87 hits in planarians. The difference in sensitivity could not be attributed to molecular weight, Log Kow or the bioconcentration factor. Of the 87 chemicals, 28 had previously been evaluated in mammalian developmental neuro- (DNT), neuro- or developmental toxicity studies. Of the 28, 20 were hits in the planarian, and 27 were hits in zebrafish. Eighteen of the 28 had previously been identified as DNT hits in mammals and were highly associated with activity in zebrafish and planarian behavioral assays in this study. Only 1 chemical (out of 28) was a false negative in both zebrafish and planarian systems. Differences in endpoint coverage and system sensitivity illustrate the value of a dual systems approach to rapidly query a large chemical-bioactivity space and provide weight-of-evidence for prioritization of chemicals for further testing

    Multi-Behavioral Endpoint Testing Of An 87-Chemical Compound Library In Freshwater Planarians

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    There is an increased recognition in the field of toxicology of the value of medium-to-high-throughput screening methods using in vitro and alternative animal models. We have previously introduced the asexual freshwater planarian Dugesia japonica as a new alternative animal model and proposed that it is particularly well-suited for the study of developmental neurotoxicology. In this paper, we discuss how we have expanded and automated our screening methodology to allow for fast screening of multiple behavioral endpoints, developmental toxicity, and mortality. Using an 87-compound library provided by the National Toxicology Program (NTP), consisting of known and suspected neurotoxicants, including drugs, flame retardants, industrial chemicals, polycyclic aromatic hydrocarbons (PAHs), pesticides and presumptive negative controls, we further evaluate the benefits and limitations of the system for medium-throughput screening, focusing on the technical aspects of the system. We show that, in the context of this library, planarians are the most sensitive to pesticides with 16/16 compounds causing toxicity and the least sensitive to PAHs, with only 5/17 causing toxicity. Furthermore, while none of the presumptive negative controls were bioactive in adult planarians, 2/5, acetaminophen and acetylsalicylic acid, were bioactive in regenerating worms. Notably, these compounds were previously reported as developmentally toxic in mammalian studies. Through parallel screening of adults and developing animals, planarians are thus a useful model to detect such developmental-specific effects, which was observed for 13 chemicals in this library. We use the data and experience gained from this screen to propose guidelines for best practices when using planarians for toxicology screens

    An economic evaluation of salt reduction policies to reduce coronary heart disease in England: a policy modeling study

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    AbstractObjectivesDietary salt intake has been causally linked to high blood pressure and increased risk of cardiovascular events. Cardiovascular disease causes approximately 35% of total UK deaths, at an estimated annual cost of £30 billion. The World Health Organization and the National Institute for Health and Care Excellence have recommended a reduction in the intake of salt in people's diets. This study evaluated the cost-effectiveness of four population health policies to reduce dietary salt intake on an English population to prevent coronary heart disease (CHD).MethodsThe validated IMPACT CHD model was used to quantify and compare four policies: 1) Change4Life health promotion campaign, 2) front-of-pack traffic light labeling to display salt content, 3) Food Standards Agency working with the food industry to reduce salt (voluntary), and 4) mandatory reformulation to reduce salt in processed foods. The effectiveness of these policies in reducing salt intake, and hence blood pressure, was determined by systematic literature review. The model calculated the reduction in mortality associated with each policy, quantified as life-years gained over 10 years. Policy costs were calculated using evidence from published sources. Health care costs for specific CHD patient groups were estimated. Costs were compared against a “do nothing” baseline.ResultsAll policies resulted in a life-year gain over the baseline. Change4life and labeling each gained approximately 1960 life-years, voluntary reformulation 14,560 life-years, and mandatory reformulation 19,320 life-years. Each policy appeared cost saving, with mandatory reformulation offering the largest cost saving, more than £660 million.ConclusionsAll policies to reduce dietary salt intake could gain life-years and reduce health care expenditure on coronary heart disease

    Studying Planarian Regeneration Aboard The International Space Station Within The Student Space Flight Experimental Program

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    The growing possibilities of space travel are quickly moving from science fiction to reality. However, to realize the dream of long-term space travel, we must understand how these conditions affect biological and physiological processes. Planarians are master regenerators, famous for their ability to regenerate from very small parts of the original animal. Understanding how this self-repair works may inspire regenerative therapies in humans. Two studies conducted aboard the International Space Station (ISS) showed that planarian regeneration is possible in microgravity. One study reported no regenerative defects, whereas the other study reported behavioral and microbiome alterations post-space travel and found that 1 of 15 planarians regenerated a Janus head, suggesting that microgravity exposure may not be without consequences. Given the limited number of studies and specimens, further microgravity experiments are necessary to evaluate the effects of microgravity on planarian regeneration. Such studies, however, are generally difficult and expensive to conduct. We were fortunate to be sponsored by the Student Spaceflight Experiment Program (SSEP) to investigate how microgravity affects regeneration of the planarian species Dugesia japonica on the ISS. While we were unable to successfully study planarian regeneration within the experimental constraints of our SSEP Mission, we systematically analyzed the cause for the failed experiment, leading us to propose a modified protocol. This work thus opens the door for future experiments on the effects of microgravity on planarian regeneration on SSEP Missions as well as for more advanced experiments by professional researchers

    Exploring decision processes in multi-agent automated contracting

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    We are interested in the problem of multi-agent contracting, in which customers must solicit the resources and capabilities of other, self-interested agents in order to accomplish their goals. Goals may involve the execution of multi-step plans, in which different steps are contracted out to different suppliers. We have focused on decision criteria for composing requests for quotations, managing the bidding process, evaluating bids, and monitoring plan execution. We have developed a testbed that allows us to study these decision behaviors. It can generate sets of plans with known statistical attributes, formulate and submit requests for quotations, generate bids with well-defined statistics, and evaluate those bids according to a number of criteria. Each of these processes is supported by an abstract interface and a series of pluggable modules with a large number of configuration parameters. Data collection and analysis tools round out the package. We will demonstrate how to take statistics from a real application domain, apply them to the simulation, and test a variety of bid-management and bid-evaluation procedures against them
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