An Investigation into the Effect of Blood Flow Restriction on Pain and Muscular Endurance in Healthy Human Participants

Objective This study compared the effect of exercise during full, partial (intermittent) and no BFR on pain and muscular endurance. Design Within-subject repeated measures cross-over study comparing full BFR (200 mmHg), partial BFR (100 mmHg) and no (control) BFR during hand-grip exercises of a bulb dynamometer (60 per minute) at 30% of their one-repetition maximum of grip strength. Setting Laboratory. Participants 20 student volunteers (male = 14, age = 22-29 years). Main outcome measures Time to exhaustion and pain perception at minute intervals during handgrip exercises. Results There were fewer (77.0 ± 34.7) handgrip exercise repetitions during full BFR compared with partial BFR (125.1 ± 37.7, p < 0.001) and fewer repetitions for partial BFR compared with no BFR (147.6 ± 11.3 repetitions, p = 0.026). Pain intensity was higher for full BFR compared with partial BFR (p = 0.045) and higher for partial BFR compared with no BFR (p < 0.001). Participants selected more total, sensory and affective pain descriptors of the Short-Form McGill Pain Questionnaire during full BFR compared with partial BFR and no BFR. Conclusion Full BFR produced severe exercise-induced pain so partial BFR may be a more acceptable training and rehabilitation aid

An NMR-based nanostructure switch for quantum logic

We propose a nanostructure switch based on nuclear magnetic resonance (NMR) which offers reliable quantum gate operation, an essential ingredient for building a quantum computer. The nuclear resonance is controlled by the magic number transitions of a few-electron quantum dot in an external magnetic field.Comment: 4 pages, 2 separate PostScript figures. Minor changes included. One reference adde

Family Caregivers Who Would Be Unwilling to Provide Care at the End of Life Again: Findings from the Health Survey for England Population Survey

BACKGROUND: Family caregivers provide significant care at the end of life. We aimed to describe caregiver characteristics, and of those unwilling to repeat this role under the same circumstances.METHODS: Observational study of adults in private households (Health Survey for England [HSE]). Caregiving questions included: whether someone close to them died within past 5 years; relationship to the deceased; provision, intensity and duration of care; supportive/palliative care services used; willingness to care again; able to carry on with life. Comparison between those willing to care again or not used univariable analyses and an exploratory multiple logistic regression. A descriptive comparison with Health Omnibus Survey (Australia) data was conducted.FINDINGS: HSE response was 64%. 2167/8861 (25%) respondents had someone close to them die in the previous 5 years. Some level of personal care was provided by 645/8861 (7.3%). 57/632 (9%) former caregivers would be unwilling to provide care again irrespective of time since the death, duration of care, education and income. Younger age (≤65; odds ratio [OR] 2.79; 95% CI 136, 5.74) and use of palliative care services (odds ratio: 1.95, 95% CI: 1.09, 3.48) showed greater willingness to provide care again. Apart from use of palliative care services, findings were remarkably similar to the Australian data.CONCLUSIONS: A significant group of caregivers would be unwilling to provide care again. Older people and those who had not used palliative care services were more likely to be unwilling to care again. Barriers preventing access for disadvantaged groups need to be overcome

Incidence, Diagnosis and Management of Injury in Sport Climbing and Bouldering: A Critical Review

Competition climbing as an Olympic sport will debut at the 2020 summer games in Tokyo. The aims of this article are to critically review the incidence of injury in sport climbing and bouldering; the pathophysiology and presentation of finger and shoulder injuries; and the diagnostic and therapeutic algorithm for finger injuries. A semisystematic approach in reviewing literature on incidence was applied. Articles were identified after searches of the following electronic databases: Discover, Academic Search Complete (EBSCO), PubMed, Embase, SPORTDiscus, and ScienceDirect. Despite methodological shortcomings of the included studies, we estimated the mean + standard deviation of the incidence rate of injury in sport climbing and bouldering from the eight studies to be 2.71 ± 4.49/1000hrs. Differential diagnosis and the clinical management of finger and shoulder injuries in climbers is challenging. An updated diagnostic and therapeutic algorithm for finger injuries is presented

Predictors of Negative Outcomes and Causes of Loss to Follow Up Among Breast Cancer Patients in Port-au-Prince, Haiti

Objective: To determine predictors of negative outcomes and causes of loss to follow-up (LTFU) in patients with breast cancer in Haiti. Design and Methods: Patients seen by Innovating Health International’s (IHI) cancer program were designated as LTFU after at least six months of non-contact (n=606). A cohort of LTFU breast cancer patients (n=101) was compared to the larger population of breast cancer patients (n=939), and a regression model constructed in order to identify risks for death and LTFU. Multiple calls were made to contact LTFU patients, and reasons for LTFU were recorded. Results: Death and LTFU status were associated with advanced stage (p\u3c0.0005), higher ECOG (p=0.011), and longer care (p\u3c0.0005; p=.03); LTFU status was lower with positive family history (p=0.022). 42.7% of LFTU patients were successfully contacted and 37.9% of these were reported deceased. The most common reasons for LTFU to clinic were obtaining care elsewhere and difficulty accessing care (due to distance, unrest, and money). Conclusions: Understanding causes of LTFU can suggest measures to reduce risk. LTFU was driven by the same factors as mortality, suggesting many “lost” patients may be deceased; this conclusion is furthermore supported by the low rate of successful recontact and high rate of death in the LTFU population. These conclusions support the need for improved palliative care outreach. Furthermore, LTFU status in Haiti is in part due to difficulties accessing care due to issues of politics, infrastructure, and economics

Deep Chandra Observations of Abell 2199: the Interplay between Merger-Induced Gas Motions and Nuclear Outbursts in a Cool Core Cluster

We present new Chandra observations of Abell 2199 that show evidence of gas sloshing due to a minor merger, as well as impacts of the radio source, 3C 338, hosted by the central galaxy, NGC 6166, on the intracluster gas. The new data are consistent with previous evidence of a Mach 1.46 shock 100" from the cluster center, although there is still no convincing evidence for the expected temperature jump. Other interpretations of this feature are possible, but none is fully satisfactory. Large scale asymmetries, including enhanced X-ray emission 200" southwest of the cluster center and a plume of low entropy, enriched gas reaching 50" to the north of the center, are signatures of gas sloshing induced by core passage of a merging subcluster about 400 Myr ago. An association between the unusual radio ridge and low entropy gas are consistent with this feature being the remnant of a former radio jet that was swept away from the AGN by gas sloshing. A large discrepancy between the energy required to produce the 100" shock and the enthalpy of the outer radio lobes of 3C 338 suggests that the lobes were formed by a more recent, less powerful radio outburst. Lack of evidence for shocks in the central 10" indicates that the power of the jet now is some two orders of magnitude smaller than when the 100" shock was formed.Comment: 17 pages, 20 figures, accepted for publication in Ap

EEG hyper-connectivity in high-risk infants is associated with later autism

- Background: It has been previously reported that structural and functional brain connectivity in individuals with autism spectrum disorders (ASD) is atypical and may vary with age. However, to date, no measures of functional connectivity measured within the first 2 years have specifically associated with a later ASD diagnosis. - Methods: In the present study, we analyzed functional brain connectivity in 14-month-old infants at high and low familial risk for ASD using electroencephalography (EEG). EEG was recorded while infants attended to videos. Connectivity was assessed using debiased weighted phase lag index (dbWPLI). At 36 months, the high-risk infants were assessed for symptoms of ASD. - Results: As a group, high-risk infants who were later diagnosed with ASD demonstrated elevated phase-lagged alpha-range connectivity as compared to both low-risk infants and high-risk infants who did not go on to ASD. Hyper-connectivity was most prominent over frontal and central areas. The degree of hyper-connectivity at 14 months strongly correlated with the severity of restricted and repetitive behaviors in participants with ASD at 3 years. These effects were not attributable to differences in behavior during the EEG session or to differences in spectral power. - Conclusions: The results suggest that early hyper-connectivity in the alpha frequency range is an important feature of the ASD neurophysiological phenotype

Horn-Coupled, Commercially-Fabricated Aluminum Lumped-Element Kinetic Inductance Detectors for Millimeter Wavelengths

We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background (CMB) studies. The LEKIDs are made from a thin aluminum film deposited on a silicon wafer and patterned using standard photolithographic techniques at STAR Cryoelectronics, a commercial device foundry. We fabricated twenty-element arrays, optimized for a spectral band centered on 150 GHz, to test the sensitivity and yield of the devices as well as the multiplexing scheme. We characterized the detectors in two configurations. First, the detectors were tested in a dark environment with the horn apertures covered, and second, the horn apertures were pointed towards a beam-filling cryogenic blackbody load. These tests show that the multiplexing scheme is robust and scalable, the yield across multiple LEKID arrays is 91%, and the noise-equivalent temperatures (NET) for a 4 K optical load are in the range 26\thinspace\pm6 \thinspace \mu \mbox{K} \sqrt{\mbox{s}}

What we don't know about time

String theory has transformed our understanding of geometry, topology and spacetime. Thus, for this special issue of Foundations of Physics commemorating "Forty Years of String Theory", it seems appropriate to step back and ask what we do not understand. As I will discuss, time remains the least understood concept in physical theory. While we have made significant progress in understanding space, our understanding of time has not progressed much beyond the level of a century ago when Einstein introduced the idea of space-time as a combined entity. Thus, I will raise a series of open questions about time, and will review some of the progress that has been made as a roadmap for the future.Comment: 15 pages; Essay for a special issue of Foundations of Physics commemorating "Forty years of string theory

A Hot Uranus Orbiting the Super Metal-rich Star HD77338 and the Metallicity - Mass Connection

We announce the discovery of a low-mass planet orbiting the super metal-rich K0V star HD77338 as part of our on-going Calan-Hertfordshire Extrasolar Planet Search. The best fit planet solution has an orbital period of 5.7361\pm0.0015 days and with a radial velocity semi-amplitude of only 5.96\pm1.74 m/s, we find a minimum mass of 15.9+4.7-5.3 Me. The best fit eccentricity from this solution is 0.09+0.25-0.09, and we find agreement for this data set using a Bayesian analysis and a periodogram analysis. We measure a metallicity for the star of +0.35\pm0.06 dex, whereas another recent work (Trevisan et al. 2011) finds +0.47\pm0.05 dex. Thus HD77338b is one of the most metal-rich planet host stars known and the most metal-rich star hosting a sub-Neptune mass planet. We searched for a transit signature of HD77338b but none was detected. We also highlight an emerging trend where metallicity and mass seem to correlate at very low masses, a discovery that would be in agreement with the core accretion model of planet formation. The trend appears to show that for Neptune-mass planets and below, higher masses are preferred when the host star is more metal-rich. Also a lower boundary is apparent in the super metal-rich regime where there are no very low-mass planets yet discovered in comparison to the sub-solar metallicity regime. A Monte Carlo analysis shows that this, low-mass planet desert, is statistically significant with the current sample of 36 planets at around the 4.5\sigma\ level. In addition, results from Kepler strengthen the claim for this paucity of the lowest-mass planets in super metal-rich systems. Finally, this discovery adds to the growing population of low-mass planets around low-mass and metal-rich stars and shows that very low-mass planets can now be discovered with a relatively small number of data points using stable instrumentation.Comment: 25 pages, 15 figures, 5 tables, accepted for publication in Ap