Development of a Ground-Based Analog to the Advanced Resistive Exercise Device Aboard the International Space Station

NASA and Wyle engineers constructed a Horizontal Exercise Fixture (HEF) that was patented in 2006. Recently modifications were made to HEF with the goal of creating a device that mimics squat exercise on the Advanced Resistive Exercise Device (ARED) and can be used by bed rest subjects who must remain supine during exercise. This project posed several engineering challenges, such as how best to reproduce the hip motions (we used a sled that allowed hip motion in the sagittal plane), how to counterweight the pelvis against gravity (we used a pulley and free-weight mechanism), and how to apply large loads (body weight plus squat load) to the shoulders while simultaneously supporting the back against gravity (we tested a standard and a safety bar that allowed movement in the subject s z-axis, both of which used a retractable plate for back support). METHODS An evaluation of the HEF was conducted with human subjects (3F, 3M), who performed sets of squat exercises of increasing load from 10-repetition maximum (RM) up to 1-RM. Three pelvic counterweight loads were tested along with each of the two back-support squat bars. Data collection included 3-dimensional ground reaction forces (GRF), muscle activation (EMG), body motion (video-based motion capture), and subjective comments. These data were compared with previous ground-based ARED study data. RESULTS All subjects in the evaluation were able to perform low- to high-loading squats on the HEF. Four of the 6 subjects preferred a pelvic counterweight equivalent to 60 percent of their body weight. Four subjects preferred the standard squat bar, whereas 2 female subjects preferred the safety bar. EMG data showed muscle activation in the legs and low back typical of squat motion. GRF trajectories and eccentric-concentric loading ratios were similar to ARED. CONCLUSION: Squat exercise performed on HEF approximated squat exercise on ARED

Toxaphene and Other Organochlorines in Arctic Ocean Fauna: Evidence for Atmospheric Delivery

Residues of the insecticide toxaphene (polychlorinated camphenes, PCCs) and other organochlorines (OCs) were determined in air, snow, seawater, zooplankton, and benthic amphipods collected from an ice island in the Canadian Arctic. The simultaneous determination of OCs in the atmospheric, hydrologic, and biologic compartments provided evidence of an atmospheric link to polar food chains. PCCs were identified and quantified using capillary gas chromatography - negative ion mass spectrometry. The order of OCs abundance in arctic air was: hexachlorocyclohexanes (HCHs) > hexachlorobenzene > PCCs > polychlorinated biphenyls (PCBs) > chlordanes > DDTs. In seawater, PCCs were exceeded only by the HCHs. Concentrations of PCBs and PCCs in two samples of benthic amphipods were the highest of the OCs detected.Key words: Arctic, Canada, pollution, organochlorines, air, water, biotaMots clés: Arctique, Canada, pollution, organochlorés, air, eau, biot

Economic crisis and the construction of a neo-liberal regulatory regime in Korea

A consistent theme of the literature on the ontology of the 1997 South Korean crisis is the key role played by regulatory failures and the growing weakness of the state. This paper seeks to briefly highlight both the insights and the limitations of this approach to understanding the crisis. Having done so, we shall set out the argument that the crisis created an opportunity for reformist Korean élites to advance their longstanding, but previously frustrated, project to create a comprehensive unambiguously neo-liberal regulatory regime. This paper will also seek to highlight the implications of our reading of the development of the Korean political economy for broader debates on economic liberalisation, crisis and the future of the developmental state

ICON 2019: International Scientific Tendinopathy Symposium Consensus: Clinical Terminology

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.Background Persistent tendon pain that impairs function has inconsistent medical terms that can influence choice of treatment.1 When a person is told they have tendinopathy by clinician A or tendinitis by clinician B, they might feel confused or be alarmed at receiving what they might perceive as two different diagnoses. This may lead to loss of confidence in their health professional and likely adds to uncertainty if they were to search for information about their condition. Clear and uniform terminology also assists inter-professional communication. Inconsistency in terminology for painful tendon disorders is a problem at numerous anatomical sites. Historically, the term ‘tendinitis’ was first used to describe tendon pain, thickening and impaired function (online supplementary figure S1). The term ‘tendinosis’ has also been used in a small number of publications, some of which were very influential.2 3 Subsequently, ‘tendinopathy’ emerged as the most common term for persistent tendon pain.4 5 To our knowledge, experts (clinicians and researchers) or patients have never engaged in a formal process to discuss the terminology we use. We believe that health professionals have not yet agreed on the appropriate terminology for painful tendon conditions.Peer reviewedFinal Accepted Versio

De Sitter and Schwarzschild-De Sitter According to Schwarzschild and De Sitter

When de Sitter first introduced his celebrated spacetime, he claimed, following Schwarzschild, that its spatial sections have the topology of the real projective space RP^3 (that is, the topology of the group manifold SO(3)) rather than, as is almost universally assumed today, that of the sphere S^3. (In modern language, Schwarzschild was disturbed by the non-local correlations enforced by S^3 geometry.) Thus, what we today call "de Sitter space" would not have been accepted as such by de Sitter. There is no real basis within classical cosmology for preferring S^3 to RP^3, but the general feeling appears to be that the distinction is in any case of little importance. We wish to argue that, in the light of current concerns about the nature of de Sitter space, this is a mistake. In particular, we argue that the difference between "dS(S^3)" and "dS(RP^3)" may be very important in attacking the problem of understanding horizon entropies. In the approach to de Sitter entropy via Schwarzschild-de Sitter spacetime, we find that the apparently trivial difference between RP^3 and S^3 actually leads to very different perspectives on this major question of quantum cosmology.Comment: 26 pages, 8 figures, typos fixed, references added, equation numbers finally fixed, JHEP versio

Contesting authentic practice and ethical authority in adventure tourism

This paper examines the discourses of authenticity and ethics used among adventure tourists regarding the use of the natural environment. In one case, full-time traveling rock climbers use their dedication to the sport and annual visits to the Red River Gorge as evidence for their authoritative voice on ethical climbing practice. While they identify the growing numbers of leisure climbers as a problem for sustainability, many also take up temporary employment as guides and are directly involved in the introduction of new climbers to the area. In another case, two groups of wilderness enthusiasts – “ADK 46ers” and “Summit Stewards” – lament the environmental and social impacts of other recreational users in the Adirondack Park. Despite being visitors themselves, Summit Stewards and 46ers use their sense of place and knowledge of Adirondack history and ecology to substantiate their authority as purveyors of ethical practice. In both cases, senses of responsibility are inspired by senses of place, but are articulated through notions of authenticity and used as justification for ethical authority. While validating their presence in these outdoor spaces, the use of such rhetoric also minimizes their own impacts yielding further tensions among user groups

Neutrino Masses with "Zero Sum" Condition: mν1+mν2+mν3=0m_{\nu_1} + m_{\nu_2} + m_{\nu_3} = 0

It is well known that the neutrino mass matrix contains more parameters than experimentalists can hope to measure in the foreseeable future even if we impose CP invariance. Thus, various authors have proposed ansatzes to restrict the form of the neutrino mass matrix further. Here we propose that $m_{\nu_1} + m_{\nu_2} + m_{\nu_3} = 0$; this ``zero sum'' condition can occur in certain class of models, such as models whose neutrino mass matrix can be expressed as commutator of two matrices. With this condition, the absolute neutrino mass can be obtained in terms of the mass-squared differences. When combined with the accumulated experimental data this condition predicts two types of mass hierarchies, with one of them characterized by $m_{\nu_3} \approx -2m_{\nu_1} \approx -2 m_{\nu_2} \approx 0.063$ eV, and the other by $m_{\nu_1} \approx -m_{\nu_2} \approx 0.054$ eV and $m_{\nu_3} \approx 0.0064$ eV. The mass ranges predicted is just below the cosmological upper bound of 0.23 eV from recent WMAP data and can be probed in the near future. We also point out some implications for direct laboratory measurement of neutrino masses, and the neutrino mass matrix.Comment: Latex 12 pages. No figures. New references adde

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter