5,065 research outputs found
Airlines and Air Mail: The Post Office and the Birth of the Commercial Aviation Industry
Conventional wisdom credits only entrepreneurs with the vision to create America’s commercial airline industry and contends that it was not until Roosevelt’s Civil Aeronautics Act of 1938 that federal airline regulation began. In Airlines and Air Mail, F. Robert van der Linden persuasively argues that Progressive republican policies of Herbert Hoover actually fostered the growth of American commercial aviation. Air mail contracts provided a critical indirect subsidy and a solid financial foundation for this nascent industry. Postmaster General Walter F. Brown used these contracts as a carrot and a stick to ensure that the industry developed in the public interest while guaranteeing the survival of the pioneering companies. Bureaucrats, entrepreneurs, and politicians of all stripes are thoughtfully portrayed in this thorough chronicle of one of America’s most resounding successes, the commercial aviation industry.
F. Robert van der Linden, curator of air transportation at the Smithsonian Institution\u27s National Air and Space Museum, is the author of The Boeing 247: The First Modern Airliner.https://uknowledge.uky.edu/upk_history_of_science_technology_and_medicine/1001/thumbnail.jp
A New Method to Determine Tooth Positions and Dental Arch Dimensions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66726/2/10.1177_00220345720510042301.pd
PEARL model for pesticide behaviour and emissions in soil-plant systems : description of the processes in FOCUS PEARL v 1.1.1
The use of pesticides in agriculture presents risks to the environment, which are increasingly evaluated by using computation models. The new PEARL model simulates the behaviour of pesticides in soil-plant systems and their emissions to the environment. The pesticide model is used in combination with the hydrological model SWAP. Various agricultural situations and ways of applying the pesticides can be simulated. The model accounts for different sorption mechanisms, in equilibrium and non-equilibriumdomains of the soil. Pesticide transport in the liquid and gas phases is described by the convection-dispersion-diffusion type equation, which is supplemented with sink terms. Comprehensive reaction schemes are processed in matrix form. The rate in first-order transformation kinetics is dependent on temperature, soil moisture content and depth in the soil. Besides computing persistence and distribution of the pesticidal compounds in soil, the model computes volatilization into the air, lateral drainage to water courses and leaching to groundwater
Alzheimer' Disease as a Disconnection Syndrome?
This paper reviews the growing amount of evidence supporting the hypothesis that Alzheimer's disease includes a disconnection syndrome. This evidence came mainly from neuropathological, electrophysiological, and neuroimaging studies. Moreover, a few recent neuropsychological studies have also explored the effects of a disconnection between cerebral areas on cognitive functioning. Finally, and more generally, the contribution of this interpretation to the understanding of Alzheimer's disease cognitive deficits is considere
Exploring Research through Design in Animal-Computer Interaction
This paper explores Research through Design (RtD) as a potential methodology for developing new interactive experiences for animals. We present an example study from an on-going project and examine whether RtD offers an appropriate framework for developing knowledge in the context of Animal-Computer Interaction, as well as considering how best to document such work. We discuss the design journey we undertook to develop interactive systems for captive elephants and the extent to which RtD has enabled us to explore concept development and documentation of research. As a result of our explorations, we propose that particular aspects of RtD can help ACI researchers gain fresh perspectives on the design of technology-enabled devices for non-human animals. We argue that these methods of working can support the investigation of particular and complex situations where no idiomatic interactions yet exist, where collaborative practice is desirable and where the designed objects themselves offer a conceptual window for future research and development
The Koala component model for consumer electronics software
Published versio
Higher rate of complications with uncemented compared to cemented total hip arthroplasty for displaced intracapsular hip fractures: A randomised controlled trial of 50 patients
Marietta van der Linden - ORCID: 0000-0003-2256-6673
https://orcid.org/0000-0003-2256-6673Replaced AM with VoR 2020-10-26Background The primary aim of this study was to compare the functional outcome of uncemented with cemented total hip arthroplasty (THA) for displaced intracapsular hip fractures. The secondary aims were to assess length of surgery, blood loss, complications and revision rate between the two groups.Methods
A prospective double-blind randomised control trial was conducted. Fifty patients’ staining an intracapsular hip fracture meeting the inclusion criteria and were randomised to either an uncemented (n=25) or cemented (n=25) THA. There were no differences (p>0.45) in age, gender, health status or preinjury hip function between the groups. The Oxford hip score (OHS), Harris Hip score (HHS), EuroQol 5-dimensional (EQ5D), timed get up-and-go (TUG), pain and patient satisfaction were used to assess outcome. These were assessed at 4, 12 and 72 months after surgery, apart from the TUG which as only assessed as 6 months.Results
The study was terminated early due to the significantly (n=8, p=0.004) higher rate of intraoperative complications in the uncemented group: three fractures of the proximal femur and five conversions to a cemented acetabular component. There were no significant (p≥0.09) differences in the functional measures (OHS, HSS, EQ5D, TUG and pain) or patient satisfaction between the groups. There was no difference in operative time (p=0.75) or blood loss (p=0.66) between the groups. There were two early revisions prior to 3-months postoperatively in the uncemented group and none in the cemented group, but this was not significant (Log Rank p=0.16).Conclusion
There was a high rate of intraoperative complications, which may be due to poor bone quality in this patient group. There were no ergonomic or functional advantages demonstrated between uncemented and cemented THA. Cemented THA should remain as the preferred choice for the treatment of intracapsular hip fractures for patients that meet the criteria for this procedure.https://doi.org/10.1007/s00590-020-02808-x31pubpu
Implementing an intrinsically integrated game on Newtonian mechanics in the classroom: outcomes in terms of conceptual understanding and transfer
Digital educational games have demonstrated large variations in learning
outcomes and transfer. Furthermore, educational games are usually embedded in a
larger educational setting. This case study evaluates in detail a lesson around
an educational game designed to foster transfer. The game, Newtons Race, is an
intrinsically integrated game on Newtonian mechanics. The learning goal of the
lesson is understanding and applying the relationship between forces and
motion. Outside of the game, lesson activities include a debriefing session, a
generalisation assignment, and an assignment on transfer situations. This
lesson was evaluated using a mixed-methods approach. A pre-post test design
(N=27) demonstrated a large significant learning effect (p = .002, d = .908).
Transfer, as measured within the posttest, was also fostered significantly. In
the qualitative part of the study, students written statements on the
worksheets and students utterances during the discussion were analyzed using
open coding. 79 percent Of all quotes were coded as scientifically correct.Comment: 25 pagers, 4 figures, 6 table
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