AN ASSESSMENT OF WORKAROUNDS FOR SPATIAL EFFECTS IN THE CASE OF BINARY PROBIT

The consequences of spatial effects on discrete choice models have not been well established. Various ad hoc workarounds have been proposed to mitigate potential estimation problems. This paper employs Monte Carlo simulation to investigate the severity of the problems introduced by spatial effects and the effectiveness of the workarounds.Research Methods/ Statistical Methods,

Physicians—Applying the Statute of Limitations in Malpractice Cases—\u3ci\u3eSpath v. Morrow\u3c/i\u3e (Neb. 1962)

Many questions are left unanswered by the adoption of the discovery rule in Nebraska, but it is clear that the court intends to enlarge the opportunities for plaintiffs to obtain relief in malpractice cases. Whether the court intends to have the discovery rule supersede the end of treatment rule, or whether it intends to have them exist concurrently, will be clarified in later decisions. The concern shown by the court for the fair treatment of the injured patient makes it probable that the court will abandon any restriction of the discovery rule and apply it to all malpractice claims

Effects of Flight Conditions at Booster Separation on Payload Weight in Orbit

A study of the principal flight parameters at booster separation was conducted to find the effect of each on the weight of the payload boosted into an earth orbit along a zero drag gravity turn trajectory. The parameters considered include Mach number (3 to 9), flight-path angle (10 deg to 55 deg), altitude (90,000 and 350,000 ft), inert weight ratio (0.05 to 0.15), and thrust-weight ratio (1.5 to 2.5), with a specific impulse of 289 seconds. Both transfer ellipse and direct orbit trajectories were considered. With either trajectory method, payload weight was highest for low initial flight-path angles and high initial Mach numbers. Of course, high initial Mach numbers require greater energy expenditures from the booster. Changes in initial altitude had little effect on payload weight, and only small gains were evident when thrust-weight ratio was increased

A tool to aid redesign of flexible transport services to increase efficiency in rural transport service provision

This research was supported by the Research Councils UK Digital Economy programme award (reference: EP/G066051/1) to the dot.rural Digital Economy Hub, at the University of Aberdeen.Peer reviewedPublisher PD

On the potential for one-way electric vehicle car-sharing in future mobility systems

This research was carried out as part of the ESPRIT project, which was funded under grant agreement no. 653395 of the European Union’s Horizon 2020 research and innovation programme.Peer reviewedPublisher PD

Undulation instability in a bilayer lipid membrane due to electric field interaction with lipid dipoles

Bilayer lipid membranes [BLMs] are an essential component of all biological systems, forming a functional barrier for cells and organelles from the surrounding environment. The lipid molecules that form membranes contain both permanent and induced dipoles, and an electric field can induce the formation of pores when the transverse field is sufficiently strong (electroporation). Here, a phenomenological free energy is constructed to model the response of a BLM to a transverse static electric field. The model contains a continuum description of the membrane dipoles and a coupling between the headgroup dipoles and the membrane tilt. The membrane is found to become unstable through buckling modes, which are weakly coupled to thickness fluctuations in the membrane. The thickness fluctuations, along with the increase in interfacial area produced by membrane buckling, increase the probability of localized membrane breakdown, which may lead to pore formation. The instability is found to depend strongly on the strength of the coupling between the dipolar headgroups and the membrane tilt as well as the degree of dipolar ordering in the membrane.Comment: 29 pages 8 fig

On the role of frameworks and smart mobility in addressing the rural mobility problem

Acknowledgements: We would like to acknowledge the European Commission in funding the SMARTA project (Contract n. No MOVE/B4/SER/2017-473/S 12.780134), which has enabled this research to take place. The insight papers and good practice cases referred to in this paper have been completed by members of the SMARTA Consortium: MemEx (IT), University of Aberdeen (UK), Transport & Mobility Leuven (BE), Vectos (UK) and European Integrated Projects (RO).Peer reviewedPostprin

Comparing the utilization and cost of health services between veterans experiencing brief and ongoing episodes of housing instability

Housing instability is associated with costly patterns of health and behavioral health service use. However, little prior research has examined patterns of service use associated with higher costs among those experiencing ongoing housing instability. To address this gap, we compared inpatient and outpatient medical and behavioral health service utilization and costs between veterans experiencing brief and ongoing episodes of housing instability. We used data from a brief screening instrument for homelessness and housing instability that has been implemented throughout the US Department of Veterans Affairs (VA) health care system to identify a national sample of veterans experiencing housing instability. Veterans were classified as experiencing either brief or ongoing housing instability, based on two consecutive responses to the instrument, and we used a series of two-part regression models to conduct adjusted comparisons of costs between veterans experiencing brief and ongoing episodes of housing instability. Among 5794 veterans screening positive for housing instability, 4934 (85%) were experiencing brief and 860 (15%) ongoing instability. The average total annual incremental cost associated with ongoing versus brief episodes of housing instability was estimated at $7573, with the bulk of this difference found in inpatient services. Cost differences resulted more from a higher probability of service use among those experiencing ongoing episodes of housing instability than from higher costs among service users. Our findings suggest that VA programmatic efforts aimed at preventing extended episodes of housing instability could potentially result in substantial cost offsets for the VA health care system.This study was supported by funding from the Department of Veterans Affairs (VA) Health Services Research & Development (HSR&D) grant IIR 13-334-3 and from the VA National Center on Homelessness Among Veterans