69 research outputs found

    Si-compatible candidates for high-K dielectrics with the Pbnm perovskite structure

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    We analyze both experimentally (where possible) and theoretically from first-principles the dielectric tensor components and crystal structure of five classes of Pbnm perovskites. All of these materials are believed to be stable on silicon and are therefore promising candidates for high-K dielectrics. We also analyze the structure of these materials with various simple models, decompose the lattice contribution to the dielectric tensor into force constant matrix eigenmode contributions, explore a peculiar correlation between structural and dielectric anisotropies in these compounds and give phonon frequencies and infrared activities of those modes that are infrared-active. We find that CaZrO_3, SrZrO_3, LaHoO_3, and LaYO_3 are among the most promising candidates for high-K dielectrics among the compounds we considered.Comment: 17 pages, 9 figures, 4 tables. Supplementary information: http://link.aps.org/supplemental/10.1103/PhysRevB.82.064101 or http://www.physics.rutgers.edu/~sinisa/highk/supp.pd

    Lessons from a Health Policy and Systems Research programme exploring the quality and coverage of newborn care in Kenya.

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    There are global calls for research to support health system strengthening in low-income and middle-income countries (LMICs). To examine the nature and magnitude of gaps in access and quality of inpatient neonatal care provided to a largely poor urban population, we combined multiple epidemiological and health services methodologies. Conducting this work and generating findings was made possible through extensive formal and informal stakeholder engagement linked to flexibility in the research approach while keeping overall goals in mind. We learnt that 45% of sick newborns requiring hospital care in Nairobi probably do not access a suitable facility and that public hospitals provide 70% of care accessed with private sector care either poor quality or very expensive. Direct observations of care and ethnographic work show that critical nursing workforce shortages prevent delivery of high-quality care in high volume, low-cost facilities and likely threaten patient safety and nurses' well-being. In these challenging settings, routines and norms have evolved as collective coping strategies so health professionals maintain some sense of achievement in the face of impossible demands. Thus, the health system sustains a functional veneer that belies the stresses undermining quality, compassionate care. No one intervention will dramatically reduce neonatal mortality in this urban setting. In the short term, a substantial increase in the number of health workers, especially nurses, is required. This must be combined with longer term investment to address coverage gaps through redesign of services around functional tiers with improved information systems that support effective governance of public, private and not-for-profit sectors

    Computer Analysis of User Interfaces Based on Repetition in Transcripts of User Sessions

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    It is generally acknowledged that the production of quality user interfaces requires a thorough understanding of the user and that this involves evaluating the interface by observing the user working with the system, or by performing human factors experiments. Such methods traditionally involve the use of video tape, protocol analysis, critical incident analysis, etc. These methods require time consuming analyses and may be invasive. In addition, the data obtained through such methods represent a relatively small portion of the use of a system. An alternative approach is to record all user input and systems output, i.e., log the user session. Such transcripts can be collected automatically and non-invasively over a long period of time. Unfortunately, this produces voluminous amounts of data. There is, therefore, a need for tools and techniques that allow an evaluator to identify potential performance and usability problems from such data. It is hypothesized that repetition of user actions is an important indicator of potential user interface problems

    Cost analysis of school-based intermittent screening and treatment of malaria in Kenya

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    <p>Abstract</p> <p>Background</p> <p>The control of malaria in schools is receiving increasing attention, but there remains currently no consensus as to the optimal intervention strategy. This paper analyses the costs of intermittent screening and treatment (IST) of malaria in schools, implemented as part of a cluster-randomized controlled trial on the Kenyan coast.</p> <p>Methods</p> <p>Financial and economic costs were estimated using an ingredients approach whereby all resources required in the delivery of IST are quantified and valued. Sensitivity analysis was conducted to investigate how programme variation affects costs and to identify potential cost savings in the future implementation of IST.</p> <p>Results</p> <p>The estimated financial cost of IST per child screened is US6.61(economiccostUS 6.61 (economic cost US 6.24). Key contributors to cost were salary costs (36%) and malaria rapid diagnostic tests (RDT) (22%). Almost half (47%) of the intervention cost comprises redeployment of existing resources including health worker time and use of hospital vehicles. Sensitivity analysis identified changes to intervention delivery that can reduce programme costs by 40%, including use of alternative RDTs and removal of supervised treatment. Cost-effectiveness is also likely to be highly sensitive to the proportion of children found to be RDT-positive.</p> <p>Conclusion</p> <p>In the current context, school-based IST is a relatively expensive malaria intervention, but reducing the complexity of delivery can result in considerable savings in the cost of intervention.</p> <p>(Costs are reported in US$ 2010).</p

    Impact of music type on motor coordination task performance among introverted and extroverted students

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    Purpose. People are interested in music. In this study, we assessed the impact of music type on objective performance.Materials and methods. We distributed 64 medical science students in Tehran into four groups: Iranian pop music, traditional music, Mozart's classical music and control groups. All participants performed the two-arm coordination test once without music and once with music (except for the control group), with an interval of 1 week. In the music groups, music was playing during the performance of the test. Participants were categorized as either introverted or extroverted and were distributed equally in the groups.Results. There was a significant decrease of test time in the second trial, observed in all music groups, and no significant difference identified in the control group. The traditional music group had less difference of mean time compared to the pop music group. The differences in the traditional and classical groups were not significantly different. In the music groups, both extroverted and introverted students decreased their test time significantly after music intervention, but extroverted students decreased more.Conclusion. Listening to music would enhance the speed of performance. Music with a higher tempo, such as pop music, increased the speed more
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