9,979 research outputs found

    Spacelab energetic ion mass spectrometer

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    Basic design criteria are given for an ion mass spectrometer for use in studying magnetospheric ion populations. The proposed instrument is composed of an electrostatic analyzer followed by a magnetic spectrometer and simultaneously measures the energy per unit and mass per unit charge of the ion species. An electromagnet is used for momentum analysis to extend the operational energy range over a much wider domain than is possible with the permanent magnets used in previous flights. The energetic ion source regions, ion energization mechanisms, field line tracing, coordinated investigations, and orbit considerations are discussed and operations of the momentum analyzer and of the electrostatic energy analyzer are examined

    Alvin titanium electrical penetrator design, manufacture, and testing : interim report

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    Under the U.S. Navy's Project TITANES a new titanium alloy pressure hull has been designed, built, and installed for use in the deep-submersible ALVIN. The Woods Hole Oceanographic Institution was assigned the task of designing, procuring and testing the through-hull electrical penetrators for the new sphere. This interim report traces the progress of this Woods Hole program from the initial design stage, through the various phases of manufacture and electrical testing, to the installation of the units in the completed hull, and the numerous laboratory~ pressure tank, and at-sea tests conducted to verify the satisfactory performance of the new penetrators. The results of all laboratory and in-service testing done to date support the conclusion that the performance of the titanium penetrators meets all of the original specifications.Office of Naval Research Contract No. NOr014-73-C-0097 NR 265-10

    Looming struggles over technology for border control

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    New technologies under development, capable of inflicting pain on masses of people, could be used for border control against asylum seekers. Implementation might be rationalized by the threat of mass migration due to climate change, nuclear disaster or exaggerated fears of refugees created by governments. We focus on taser anti-personnel mines, suggesting both technological countermeasures and ways of making the use of such technology politically counterproductive. We also outline several other types of ā€˜non-lethalā€™ technology that could be used for border control and raise human rights concerns: high-powered microwaves, armed robots, wireless tasers, acoustic devices/vortex rings, ionizing and pulsed energy lasers, chemical calmatives, convulsants, bioregulators and malodurants. Whether all these possible border technologies will be implemented is a matter for speculation, but their serious human rights implications warrant advance scrutiny

    Economic benefits of Mt. Cook National Park

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    Market and non-market valued decisions are associated with New Zealand's system of national parks. The use benefits of Mount Cook National Park are not priced by the market mechanism, whereas many of the inputs necessary to operate and maintain the Park are priced. Estimates of the economic benefits are relevant information when deciding upon the allocation of resources to, and within, a system of national parks. In 1984, the consumers' surplus for adult New Zealand visitors was about 2.2million.Anestimateofthenetnationalbenefitsisgivenbytheconsumersā€²surplusobtainedbyNewZealandvisitors,plusthenetbenefitsassociatedwithforeignvisitors,lessthecostofParkmanagementandlandrental.ThenetbenefitofMountCookNationalPark,asitwasin1984,islikelytobepositive,indicatingthatthebenefitsassociatedwiththecurrentusepatternofresourcesexceedstheiropportunitycosttothenation.However,thisresultcannotbeusedtoestablishtheoptimalityofcurrentexpenditureandmanagement.Approximately170,000adultsvisitedMountCookNationalParkover1984;292.2 million. An estimate of the net national benefits is given by the consumers' surplus obtained by New Zealand visitors, plus the net benefits associated with foreign visitors, less the cost of Park management and land rental. The net benefit of Mount Cook National Park, as it was in 1984, is likely to be positive, indicating that the benefits associated with the current use pattern of resources exceeds their opportunity cost to the nation. However, this result cannot be used to establish the optimality of current expenditure and management. Approximately 170,000 adults visited Mount Cook National Park over 1984; 29% were from New Zealand, 25% were from Australia, 18% were from the United States, and 7% were from Japan. Visitors to the Park spend money in towns and villages in the Mackenzie Basin area. Average adult visitor expenditure in the Mackenzie Basin area is 58. These expenditures give rise to secondary economic benefits and create opportunities for regional development. Visitor expenditures in the Mackenzie Basin area are associated with 13.4millionofadditionalregionaloutput,13.4 million of additional regional output, 6.8 million of additional regional income, and 196 jobs. These effects derive their significance from regional objectives; they are not indicators of the national benefits associated with Mount Cook National Park

    Consequences of a changing US strategy in the global HIV investment landscape.

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    OBJECTIVE: The global fight against HIV/AIDS in Africa has long been a focus of US foreign policy, but this could change if the federal budget for 2018 proposed by the US Office of Management and Budget is adopted. We aim to inform public and Congressional debate around this issue by evaluating the historical and potential future impact of US investment in the African HIV response. DESIGN/METHODS: We use a previously published mathematical model of HIV transmission to characterize the possible impact of a series of financial scenarios for the historical and future AIDS response across Sub-Saharan Africa. RESULTS: We find that US funding has saved nearly five million adults in Sub-Saharan Africa from AIDS-related deaths. In the coming 15 years, if current numbers on antiretroviral treatment are maintained without further expansion of programs (the proposed US strategy), nearly 26 million new HIV infections and 4.4 million AIDS deaths may occur. A 10% increase in US funding, together with ambitious domestic spending and focused attention on optimizing resources, can avert up to 22 million HIV infections and save 2.3 million lives in Sub-Saharan Africa compared with the proposed strategy. CONCLUSION: Our synthesis of available evidence shows that the United States has played, and could continue to play, a vital role in the global HIV response. Reduced investment could allow more than two million avoidable AIDS deaths by 2032, whereas continued leadership by the United States and other countries could bring UNAIDS targets for ending the epidemic into reach

    Single Nucleotide Polymorphismā€“Based Validation of Exonic Splicing Enhancers

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    Because deleterious alleles arising from mutation are filtered by natural selection, mutations that create such alleles will be underrepresented in the set of common genetic variation existing in a population at any given time. Here, we describe an approach based on this idea called VERIFY (variant elimination reinforces functionality), which can be used to assess the extent of natural selection acting on an oligonucleotide motif or set of motifs predicted to have biological activity. As an application of this approach, we analyzed a set of 238 hexanucleotides previously predicted to have exonic splicing enhancer (ESE) activity in human exons using the relative enhancer and silencer classification by unanimous enrichment (RESCUE)-ESE method. Aligning the single nucleotide polymorphisms (SNPs) from the public human SNP database to the chimpanzee genome allowed inference of the direction of the mutations that created present-day SNPs. Analyzing the set of SNPs that overlap RESCUE-ESE hexamers, we conclude that nearly one-fifth of the mutations that disrupt predicted ESEs have been eliminated by natural selection (odds ratio = 0.82 Ā± 0.05). This selection is strongest for the predicted ESEs that are located near splice sites. Our results demonstrate a novel approach for quantifying the extent of natural selection acting on candidate functional motifs and also suggest certain features of mutations/SNPs, such as proximity to the splice site and disruption or alteration of predicted ESEs, that should be useful in identifying variants that might cause a biological phenotype

    Simian immunodeficiency virus infection in wild-caught chimpanzees from Cameroon

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    Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study

    The influence of emotional reaction on help seeking by victims of school bullying

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    Research has started to focus on how victims of school bullying cope, but there is still very little understanding if why pupils cope in one way and not another. This paper aimed to examine the effects of gender, school-stage, frequency of victimization and different emotions (anger, vengeance, self-pity, indifference, and helplessness) upon the choice of social support that children report using. Questionnaires were completed by 6282 Maltese schoolchildren aged between 9 and 14 years old. Analyses revealed that specific patterns of emotion and victimization predict whether pupils report using certain sources of social support. Results are discussed in relation to their relevance for possible intervention, future research needs and implications for the theoretical framework used
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