1,154 research outputs found

    A head-up display for mid-air drone recovery

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    During mid-air retrieval of parachute packages, the absence of a natural horizon creates serious difficulties for the pilot of the recovery helicopter. A head-up display (HUD) was tested in an attempt to solve this problem. Both a roll-stabilized HUD and a no-roll (pitch only) HUD were tested. The results show that fewer missed passes occurred with the roll-stabilized HUD when the horizon was obscured. The pilots also reported that the workload was greatly reduced. Roll-stabilization was required to prevent vertigo when flying in the absence of a natural horizon. Any HUD intended for mid-air retrieval should display pitch, roll, sideslip, airspeed, and vertical velocity

    Improving School Leadership: The Promise of Cohesive Leadership Systems

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    Describes Wallace grantees' work to create a cohesive leadership system of coordinated policies between states and districts and across state agencies, states' and districts' efforts to forge cohesive policies, and the impact on instructional leadership

    Corneoscleral laceration and ocular burns caused by electronic cigarette explosions

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    PURPOSE: To report cases of acute globe rupture and bilateral corneal burns from electronic cigarette (EC) explosions. METHODS: Case series. RESULTS: We describe a series of patients with corneal injury caused by EC explosions. Both patients suffered bilateral corneal burns and decreased visual acuity, and one patient sustained a unilateral corneoscleral laceration with prolapsed iris tissue and hyphema. A review of the scientific literature revealed no prior reported cases of ocular injury secondary to EC explosions; however, multiple media and government agency articles describe fires and explosions involving ECs, including at least 4 with ocular injuries. CONCLUSIONS: Given these cases and the number of recent media reports, ECs pose a significant public health risk. Users should be warned regarding the possibility of severe injury, including sight-threatening ocular injuries ranging from corneal burns to full-thickness corneoscleral laceration

    Modelling survival and connectivity of Mnemiopsis leidyi in the south-western North Sea and Scheldt estuaries

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    Three different models were applied to study the reproduction, survival and dispersal of Mnemiopsis leidyi in the Scheldt estuaries and the southern North Sea: a high-resolution particle tracking model with passive particles, a low-resolution particle tracking model with a reproduction model coupled to a biogeochemical model, and a dynamic energy budget (DEB) model. The results of the models, each with its strengths and weaknesses, suggest the following conceptual situation: (i) the estuaries possess enough retention capability to keep an overwintering population, and enough exchange with coastal waters of the North Sea to seed offshore populations; (ii) M. leidyi can survive in the North Sea, and be transported over considerable distances, thus facilitating connectivity between coastal embayments; (iii) under current climatic conditions, M. leidyi may not be able to reproduce in large numbers in coastal and offshore waters of the North Sea, but this may change with global warming; however, this result is subject to substantial uncertainty. Further quantitative observational work is needed on the effects of temperature, salinity and food availability on reproduction and on mortality at different life stages to improve models such as used here

    Physical Function, Cognitive Function, and Aortic Stiffness in Older Adults

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    Please view abstract in the attached PDF file

    Radiation Fields in the Vicinity of Compact Accelerator Neutron Generators

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    Intense pulsed radiation fields emitted from sealed tube neutron generators provide a challenge for modern health physics survey instrumentation. The spectral sensitivity of these survey instruments requires calibration under realistic field conditions while the pulsed emission characteristics of neutron generators can vary from conditions of steady-state operation. As a general guide for assessing radiological conditions around neutron generators, experiments and modeling simulations have been performed to assess radiation fields near DD and DT neutron generators. The presence of other materials and material configurations can also have important effects on the radiation dose fields around compact accelerator neutron generators

    An Evaluation of MacArthur's Window of Opportunity: Preserving Affordable Rental Housing Initiative

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    In this report, we describe the seven strategies by which the MacArthur Foundation sought ambitious changes in the preservation of affordable rental housing. In brief, these strategies were to* support a cadre of large nonprofit owners of affordable rental housing to both preserve rental housing and act as spokespersons for preservation* increase capital for preservation by investing in special-purpose vehicles, such as preservation-themed loan funds* invest in regional interagency partnerships to retain affordable rental housing* develop business practices, tools, and research for or about preservation* provide loans and grants directly to state and local government agencies that themselves fund preservation transactions* promote low-income tenants' rights to remain in and advocate for affordable rental housing* improve the funding, regulatory, and legislative context for preservation through the foundation's combined investments in nonprofit owners, networks of nonprofit owners, special-purpose vehicles, state and local government agencies, and advocates

    Transthoracic echocardiography of hypertrophic cardiomyopathy in adults: a practical guideline from the British Society of Echocardiography.

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    Hypertrophic cardiomyopathy (HCM) is common, inherited and characterised by unexplained thickening of the myocardium. The British Society of Echocardiography (BSE) has recently published a minimum dataset for transthoracic echocardiography detailing the core views needed for a standard echocardiogram. For patients with confirmed or suspected HCM, additional views and measurements are necessary. This guideline, therefore, supplements the minimum dataset and describes a tailored, stepwise approach to the echocardiographic examination, and echocardiography's position in the diagnostic pathway, before advising on the imaging of disease complications and invasive treatments

    Trends in multiple recurrent health complaints in 15-year-olds in 35 countries in Europe, North America and Israel from 1994 to 2010

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    Publisher Copyright: © 2015 The Author. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.Background: Health complaints are a good indicator of an individual's psychosocial health and well-being. Studies have shown that children and adolescents report health complaints which can cause significant individual burden. Methods: Using data from the international Health Behaviour in School-aged Children study, this article describes trends in multiple recurrent health complaints (MHC) in 35 countries among N = 237 136 fifteen-year-olds from 1994 to 2010. MHC was defined as the presence of two or more health complaints at least once a week. Logistic regression analysis was performed to evaluate trends across the five survey cycles for each country. Results: Lowest prevalence throughout the period 1994-2010 was 16.9% in 1998 in Austria and highest in 2006 in Israel (54.7%). Overall, six different trend patterns could be identified: No linear or quadratic trend (9 countries), linear decrease (7 countries), linear increase (5 countries), U-shape (4 countries), inverted U-shape (6 countries) and unstable (4 countries). Conclusion: Trend analyses are valuable in providing hints about developments in populations as well as for benchmarking and evaluation purposes. The high variation in health complaints between the countries requires further investigation, but may also reflect the subjective nature of health complaints.publishersversionPeer reviewe
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