Variations in propagation delay times for line ten (TV) based time transfers

Variation in the propagation delay for a 30 km TV (Line Ten) radio link was evaluated for a series of 30 independent measurements. Time marks from TV Channel 5 WTTG in Washington, D.C. were simultaneously measured at the Johns Hopkins University Applied Physics Laboratory and at the United States Naval Observatory against each stations' local cesium standard clocks. Differences in the stations' cesium clocks were determined by portable cesium clock transfers. Thirty independent timing determinations were made. The root mean square deviation in the propagation delay calculated from the timing determinations was 11 ns. The variations seen in the propagation delays are believed to be caused by environmental factors and by errors in the portable clock timing measurements. In correlating the propagation delay variations with local weather conditions, only a moderate dependence on air temperature and absolute humidity was found

Circuit minimizes current drain caused by neon indicator lamps

Circuit lights neon lamp by back leakage current of the driving transistor, rather than by the transistors saturation or ''on-state'' current, thereby eliminating lowering of the voltage necessary for indication. Circuit has operating speed greater than indication circuit using a saturation principle and aids in power rationing

OPTION WEALTH AND BEQUEST VALUES: THE VALUE OF PROTECTING FUTURE GENERATIONS FROM THE HEALTH RISKS OF NUCLEAR WASTE STORAGE

We devise a simple model of intergenerational altruism under uncertainty. We present an estimable form of the model that relies on a few, plausible, assumptions. We apply the model to data collected in a survey of Southern Nevadans concerning the proposed Yucca Mountain Nuclear Waste Repository in Nye County, NV. We find strong evidence of a bequest motive. Approximately one third of the option wealth lost by households near the repository can be attributed to costs to future generations.Resource /Energy Economics and Policy,

The inter-relation between policy and practice for transitions from hospital to home: An ethnographic case study in England’s National Health Service

© 2014 Shaw et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.No abstract available (poster presentation)

Employer Policies and Practices to Manage and Prevent Disability: Conclusion to the Special Issue

Purpose Research of employer policies and practices to manage and prevent disability spans many disciplines and perspectives, and there are many challenges related to stakeholder collaboration, data access, and interventions. The purpose of this article is to synthesize the findings from a conference and year-long collaboration among a group of invited researchers intended to spur new research innovations in this field. Methods A multidisciplinary team of 26 international researchers with published research in employer-based disability management or related fields were invited to attend a 3-day conference in Hopkinton, Massachusetts, USA. The conference goals were to review the status of current research of workplace disability management and prevention, examine its relevance for employer decision-making, compare conceptual frameworks or theoretical perspectives, and recommend future research directions. In this paper, we summarize key points from the 6 resulting papers, compare them with an earlier 2005 conference on improving return-to-work research, and conclude with recommendations for further overarching research directions. Results/Conclusion In comparison with the 2005 conference, a greater emphasis was placed on organizational and social factors, employer roles and responsibilities, methods of implementation, non-clinical approaches, and facilitating stay-at-work as well as return-to-work. A special panel of employer consultants and representatives who were featured at the 2015 conference reinforced the importance of organizational culture, leadership style, and financial decision-making strategies at the employer level. Based on the conference proceedings, we recommend that future research in this area should strive for: (a) broader inclusion of workers and workplaces; (b) attention to multilevel influences in the workplace; (c) a focus on social as well as physical aspects of work; (d) earlier employer collaboration efforts; (e) more attention to implementation factors; and (f) a broader assessment of possible outcome domains

The Productivity of Pharmaceuticals in Improving Health: An Analysis of the OECD Health Data

Although a number of studies have been conducted on health production functions, little attention has been given to pharmaceuticals as a separate input into the production of health. Building upon existing published work, this paper uses an alternative specification and more recent data to estimate the effect of pharmaceutical expenditures on levels of health in the member countries of the Organization for Economic Cooperation and Development (OECD). In a sample of developed countries, we found that pharmaceutical consumption, as measured by per capita drug expenditures, has a positive effect on life expectancy at advanced ages. The marginal effect of pharmaceutical consumption is consistent with estimates that have been reported previously but appears to decline with increasing age. Over the past few years, the substantial and disproportionate growth of pharmaceutical expenditures for public and private payers in the U.S. has led to calls for regulatory intervention (e.g., price controls). However, our research suggests that increases in drug spending may yield further increases in life expectancy.Health production, life expectancy, pharmaceuticals, OECD, ecological studies

Effects of systematic errors on the mixing ratios of trace gases obtained from occulation spectra

The influence of systematic errors in the parameters of the models describing the geometry and the atmosphere on the profiles of trace gases retrieved from simulated solar occultation spectra, collected at satellite altitudes, is investigated. Because of smearing effects and other uncertainties, it may be preferable to calibrate the spectra internally by measuring absorption lines of an atmospheric gas such as CO2 whose vertical distribution is assumed rather than to relay on externally supplied information

Sanitizing the fortress: protection of ant brood and nest material by worker antibiotics

Social groups are at particular risk for parasite infection, which is heightened in eusocial insects by the low genetic diversity of individuals within a colony. To combat this, adult ants have evolved a suite of defenses to protect each other, including the production of antimicrobial secretions. However, it is the brood in a colony that are most vulnerable to parasites because their individual defenses are limited, and the nest material in which ants live is also likely to be prone to colonization by potential parasites. Here, we investigate in two ant species whether adult workers use their antimicrobial secretions not only to protect each other but also to sanitize the vulnerable brood and nest material. We find that, in both leaf-cutting ants and weaver ants, the survival of the brood was reduced and the sporulation of parasitic fungi from them increased, when the workers nursing them lacked functional antimicrobial-producing glands. This was the case for both larvae that were experimentally treated with a fungal parasite (Metarhizium) and control larvae which developed infections of an opportunistic fungal parasite (Aspergillus). Similarly, fungi were more likely to grow on the nest material of both ant species if the glands of attending workers were blocked. The results show that the defense of brood and sanitization of nest material are important functions of the antimicrobial secretions of adult ants and that ubiquitous, opportunistic fungi may be a more important driver of the evolution of these defenses than rarer, specialist parasites

Dynamics of trusses having nonlinear joints

The transient analysis of trusses having nonlinear joints can be accomplished using the residual force technique. The technique was applied a two degree of freedom spring mass system, a four bay planar truss, and an actual ten bay deployable truss. Joints chosen for analysis were the nonlinear gap joints and the linear Voigt joints. Results from the nonlinear gap analyses generally indicate that coupling between the modes can display some interesting effects during free vibration. One particularly interesting effect was that the damping of the structure appeared to be higher than could be accounted for from modal damping alone. Energy transferral from the lower to the higher modes was found to exist as a result of the modal coupling. The apparently increased damping was due to the fact that the energy transferred to the higher modes is inherently dissipated more quickly. Another interesting phenomenon was that the lower modes could drive the higher modes even during free vibration and that these modes could display a rather large quasi-steady state behavior even when modal damping was present. Gaps were also found to increase the amplitude and period of the free vibration response as expected

Near-infrared counterparts of three transient very faint neutron star X-ray binaries

We present near-infrared (NIR) imaging observations of three transient neutron star X-ray binaries, SAX J1753.5-2349, SAX J1806.5-2215 and AX J1754.2-2754. All three sources are members of the class of `very faint' X-ray transients which exhibit X-ray luminosities $L_X\lesssim10^{36}$ erg s$^{-1}$. The nature of this class of sources is still poorly understood. We detect NIR counterparts for all three systems and perform multi-band photometry for both SAX J1753.5-2349 and SAX J1806.5-2215, including narrow-band Br$_{\gamma}$ photometry for SAX J1806.5-2215. We find that SAX J1753.5-2349 is significantly redder than the field population, indicating that there may be absorption intrinsic to the system, or perhaps a jet is contributing to the infrared emission. SAX J1806.5-2215 appears to exhibit absorption in Br$_{\gamma}$, providing evidence for hydrogen in the system. Our observations of AX J1754.2--2754 represent the first detection of a NIR counterpart for this system. We find that none of the measured magnitudes are consistent with the expected quiescent magnitudes of these systems. Assuming that the infrared radiation is dominated by either the disc or the companion star, the observed magnitudes argue against an ultracompact nature for all three systems.Comment: 10 pages, 10 figures, accepted for publication in MNRA