A Large-Diameter Hollow-Shaft Cryogenic Motor Based on a Superconducting Magnetic Bearing for Millimeter-Wave Polarimetry

In this paper we present the design and measured performance of a novel cryogenic motor based on a superconducting magnetic bearing (SMB). The motor is tailored for use in millimeter-wave half-wave plate (HWP) polarimeters, where a HWP is rapidly rotated in front of a polarization analyzer or polarization-sensitive detector. This polarimetry technique is commonly used in cosmic microwave background (CMB) polarization studies. The SMB we use is composed of fourteen yttrium barium copper oxide (YBCO) disks and a contiguous neodymium iron boron (NdFeB) ring magnet. The motor is a hollow-shaft motor because the HWP is ultimately installed in the rotor. The motor presented here has a 100 mm diameter rotor aperture. However, the design can be scaled up to rotor aperture diameters of approximately 500 mm. Our motor system is composed of four primary subsystems: (i) the rotor assembly, which includes the NdFeB ring magnet, (ii) the stator assembly, which includes the YBCO disks, (iii) an incremental encoder, and (iv) the drive electronics. While the YBCO is cooling through its superconducting transition, the rotor is held above the stator by a novel hold and release mechanism (HRM). The encoder subsystem consists of a custom-built encoder disk read out by two fiber optic readout sensors. For the demonstration described in this paper, we ran the motor at 50 K and tested rotation frequencies up to approximately 10 Hz. The feedback system was able to stabilize the the rotation speed to approximately 0.4%, and the measured rotor orientation angle uncertainty is less than 0.15 deg. Lower temperature operation will require additional development activities, which we will discuss

Global shifts in mammalian population trends reveal key predictors of virus spillover risk.

Emerging infectious diseases in humans are frequently caused by pathogens originating from animal hosts, and zoonotic disease outbreaks present a major challenge to global health. To investigate drivers of virus spillover, we evaluated the number of viruses mammalian species have shared with humans. We discovered that the number of zoonotic viruses detected in mammalian species scales positively with global species abundance, suggesting that virus transmission risk has been highest from animal species that have increased in abundance and even expanded their range by adapting to human-dominated landscapes. Domesticated species, primates and bats were identified as having more zoonotic viruses than other species. Among threatened wildlife species, those with population reductions owing to exploitation and loss of habitat shared more viruses with humans. Exploitation of wildlife through hunting and trade facilitates close contact between wildlife and humans, and our findings provide further evidence that exploitation, as well as anthropogenic activities that have caused losses in wildlife habitat quality, have increased opportunities for animal-human interactions and facilitated zoonotic disease transmission. Our study provides new evidence for assessing spillover risk from mammalian species and highlights convergent processes whereby the causes of wildlife population declines have facilitated the transmission of animal viruses to humans

An inquiry concerning A fourth service of supply.

http://www.archive.org/details/inquiryconcernin00smilU.S. Navy (U.S.N.) author

The relationship between physical ill-health and mental ill-health in adults with intellectual disabilities

Background: People with intellectual disabilities face a much greater burden and earlier onset of physical and mental ill‐health than the general adult population. Physical–mental comorbidity has been shown to result in poorer outcomes in the general population, but little is known about this relationship in adults with intellectual disabilities. Aims: To identify whether physical ill‐health is associated with mental ill‐health in adults with intellectual disabilities and whether the extent of physical multi‐morbidity can predict the likelihood of mental ill‐health. To identify any associations between types of physical ill‐health and mental ill‐health. Method: A total of 1023 adults with intellectual disabilities underwent comprehensive health assessments. Binary logistic regressions were undertaken to establish any association between the independent variables: total number of physical health conditions, physical conditions by International Classification of Disease‐10 chapter and specific physical health conditions; and the dependent variables: problem behaviours, mental disorders of any type. All regressions were adjusted for age, gender, level of intellectual disabilities, living arrangements, neighbourhood deprivation and Down syndrome. Results: The extent of physical multi‐morbidity was not associated with mental ill‐health in adults with intellectual disabilities as only 0.8% of the sample had no physical conditions. Endocrine disease increased the risk of problem behaviours [odds ratio (OR): 1.22, 95% confidence interval (CI): 1.02–1.47], respiratory disease reduced the risk of problem behaviours (OR: 0.73, 95% CI: 0.54–0.99) and mental ill‐health of any type (OR: 0.73, 95% CI: 0.58–0.92), and musculoskeletal disease reduced the risk of mental ill‐health of any type (OR: 0.84, 95% CI: 0.73–0.98). Ischaemic heart disease increased the risk of problem behaviours approximately threefold (OR: 3.29, 95% CI: 1.02–10.60). Conclusions: The extent of physical multi‐morbidity in the population with intellectual disabilities is overwhelming, such that associations are not found with mental ill‐health. Mental health interventions and preventative measures are essential for the entire population with intellectual disabilities and should not be focussed on subgroups based on overall health burden