2,266 research outputs found

    Environmental forensic evidence from perchlorate in dust fall

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    Summer in Malta is accompanied by fireworks as part of the numerous (about 85) religious festivals (festa) that occur throughout the period. We attempted to establish whether firework activity is truly following official trade statistics, which imply a decreasing trend, or otherwise. Firework manufacture critically depends on the availability of oxidising agents, two of which (KNO3, KClO3) being controlled by permits but not potassium perchlorate (KClO4) which is freely available. Recent changes in legislation have slightly decreased the quantity of KClO3 and increased that of KNO3 and according to official trade statistics, consumption of KClO4 has decreased from 17 t/a in 2010 to ≈ 2.5 t/a during 2011--2014. However, from levels of perchlorate in dust fall and rate of total deposition we calculated the quantity of KClO4 used during 2012 and obtained ≥ 90 t/a, 36 times the official figure. This situation is serious since the danger of accidental explosion during manufacture escalates as production intensifies. Also, contamination of the environment by firework-waste appears destined to remain high with possible consequent effects on human health.peer-reviewe

    Incentive Design and Trust: Comparing the Effects of Tournament and Team-Based Incentives on Trust

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    We explore the extent to which the structure of incentives affects trust. We hypothesize that the degree to which different incentive mechanisms emphasize competition (via the perceived intentions of others) and entitlements (via the perceived property rights) will affect individuals’ subsequent behavior. In our experiment, bargaining pairs earned endowments through either tournaments or team-based incentives. Participants engaged in a subsequent trust game in which the sender had access to the total endowment generated by the pair. We find that the structure of the incentive mechanisms has asymmetric effects on observed trust in which participants’ relative performance framed trusting behavior.trust, incentives, experiments, tournaments

    The production and deployment of an on-line video learning bank in a skills training environment

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    This paper describes the introduction of videos as aids in clinical skills teaching. Although the process explored focuses on a nursing clinical skills environment it is relevant to many other disciplines. With the introduction of the pre-registration degree in nursing in Ireland in 2002, the formerly hospital-based schools of nursing amalgamated into larger programmes with their affiliated higher education institutes (HEIs). The result was a considerable increase in class sizes. The current average annual cohort in the School of Nursing, Dublin City University (DCU) is 240 students. This has resulted in a need to review the way we teach clinical skills on campus. These skills form a large part of the programme and are taught to students in the school-based simulated nursing environment to prepare them for their practical experience in the clinical environment. Until 2006 the skills had been taught to groups of 25-30 students using a demonstration and practice technique. This teaching method has posed a number of problems: •Learning experiences vary depending on the mix of demonstration and practice in each session. •It can be difficult for students to absorb all of the information presented in a single demonstration. •It is highly resource intensive. It was decided that video technology incorporating a large scale deployment of skills videos over a video web server, in conjunction with a shift in emphasis in the teaching contact sessions could offer a useful tool to aid the teaching process. This paper will discuss the production process, the implementation of the project in the teaching environment and the evaluation findings

    The dynamics of occupational segregation in comparative context

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    Nanotexture influence of BaTiO3 particles on piezoelectric behaviour of PA 11/BaTiO3 nanocomposites

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    The piezoelectric activity of a hybrid ferroelectric nanocomposite, i.e. polyamide 11/barium titanate (BT), has been investigated for different loadings of BT particles. The BT volume fraction (/) was ranging from 0.024 to 0.4 with a particle size of 50, 100, 300 and 700 nm. The influence of polarization mode on the piezoelectric behaviour has been studied. The magnitude of the poling field used in this study is in the same order of magnitude of the one used for bulk BT i.e. significantly lower than for piezoelectric polymers. The optimum piezoelectric coefficient is reached when the amorphous phase of the polymeric matrix is in the liquid state i.e. for a polarization temperature higher than the glass transition and for time constant allowing macromolecular mobility. The composite piezoelectric activity decreases for particles size lower than 300 nm due to the loss of the tetragonal phase. The nanotexture of these particles has been investigated by transmission electron microscopy (TEM) and high-resolution TEM. A core shell structure has been observed. An increase of the longitudinal piezoelectric strain coefficient d33 with the raising of BT volume fraction was shown. Contrary to inorganic piezoelectric ceramics, the dielectric permittivity of hybrid composites remains moderate; therefore it allows the piezoelectric voltage coefficient of composites to be higher than ceramics

    The transfer of IgA from mucus to plasma and the implications for diagnosis and control of nematode infections

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    Immunoglobulin A (IgA) activity has been associated with reduced growth and fecundity of Teladorsagia circumcincta. IgA is active at the site of infection in the abomasal mucus. However, while IgA activity in abomasal mucus is not easily measured in live animals without invasive methods, IgA activity can be readily detected in the plasma, making it a potentially valuable tool in diagnosis and control. We used a Bayesian statistical analysis to quantify the relationship between mucosal and plasma IgA in sheep deliberately infected with T. circumcincta. The transfer of IgA depends on mucosal IgA activity as well as its interaction with worm number and size; together these account for over 80% of the variation in plasma IgA activity. By quantifying the impact of mucosal IgA and worm number and size on plasma IgA, we provide a tool that can allow more meaningful interpretation of plasma IgA measurements and aid the development of efficient control programmes
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