Background. The risk of COVID-19 infection in transplant recipients (TRs) is unknown. Patients on dialysis may be exposed to greater risk of infection due to an inability to isolate. Consideration of these competing risks is important before restarting suspended transplant programs. This study compared outcomes in kidney and kidney/pancreas TRs with those on the waiting list, following admission with COVID-19 in a high-prevalence region. Methods. Audit data from all 6 London transplant centers were amalgamated. Demographic and laboratory data were collected and outcomes included mortality, intensive care (ITU) admission, and ventilation. Adult patients who had undergone a kidney or kidney/pancreas transplant, and those active on the transplant waiting list at the start of the pandemic were included. Results. One hundred twentyone TRs and 52 waiting list patients (WL) were admitted to hospital with COVID-19. Thirty-six TR died (30%), while 14 WL patients died (27% P = 0.71). There was no difference in rates of admission to ITU or ventilation. Twenty-four percent of TR required renal replacement therapy, and 12% lost their grafts. Lymphocyte nadir and D-dimer peak showed no difference in those who did and did not die. No other comorbidities or demographic factors were associated with mortality, except for age (odds ratio of 4.3 [95% CI 1.8-10.2] for mortality if aged over 60 y) in TR. Conclusions. TRs and waiting list patients have similar mortality rates after hospital admission with COVID-19. Mortality was higher in older TRs. These data should inform decisions about transplantation in the COVID era.

Emerging infectious diseases (EIDs) are typically characterized by novelty (recent detection) and by increasing incidence, distribution, and/or pathogenicity. Ophidiomycosis, also called snake fungal disease, is caused by the fungus Ophidiomyces ophidiicola (formerly “ophiodiicola”). Ophidiomycosis has been characterized as an EID and as a potential threat to populations of Nearctic snakes, sparking over a decade of targeted research. However, the severity of this threat is unclear. We reviewed the available literature to quantify incidence and effects of ophidiomycosis in Nearctic snakes, and to evaluate whether the evidence supports the ongoing characterization of ophidiomycosis as an EID. Data from Canada remain scarce, so we supplemented the literature review with surveys for O. ophidiicola in the Canadian Great Lakes region. Peer-reviewed reports of clinical signs consistent with ophidiomycosis in free-ranging, Nearctic snakes date back to at least 1998, and retrospective molecular testing of samples extend the earliest confirmed record to 1986. Diagnostic criteria varied among publications (n = 33), confounding quantitative comparisons. Ophidiomycosis was diagnosed or suspected in 36/121 captive snakes and was fatal in over half of cases (66.7%). This result may implicate captivity-related stress as a risk factor for mortality from ophidiomycosis, but could also reflect reporting bias (i.e., infections are more likely to be detected in captive snakes, and severe cases are more likely to be reported). In contrast, ophidiomycosis was diagnosed or suspected in 441/2,384 free-ranging snakes, with mortality observed in 43 (9.8 %). Ophidiomycosis was only speculatively linked to population declines, and we found no evidence that the prevalence of the pathogen or disease increased over the past decade of targeted research. Supplemental surveys and molecular (qPCR) testing in Ontario, Canada detected O. ophidiicola on 76 of 657 free-ranging snakes sampled across ~136,000 km2. The pathogen was detected at most sites despite limited and haphazard sampling. No large-scale mortality was observed. Current evidence supports previous suggestions that the pathogen is a widespread, previously unrecognized endemic, rather than a novel pathogen. Ophidiomycosis may not pose an imminent threat to Nearctic snakes, but further research should investigate potential sublethal effects of ophidiomycosis such as altered reproductive success that could impact population growth, and explore whether shifting environmental conditions may alter host susceptibility.

A new X-ray undulator has been designed and constructed which produces linearly polarized X-rays in which the plane of polarization can be oriented to a user selectable angle, from horizontal to vertical. Based on the Apple-II elliptically polarizing undulator (EPU), the undulator rotates the angle of the linear polarization by a simple longitudinal motion of the undulator magnets. Combined with the circular and elliptical polarization capabilities of the EPU operating in the standard mode, this new undulator produces soft X-ray radiation with versatile polarization control. This paper describes the magnetic structure of the device and presents an analysis of the magnetic ®eld with varying undulator parameters. The variable linear polarization capability is then exhibited by measuring the X-ray absorption spectrum of an oriented polytetra¯uoroethylene thin ®lm. This experiment, which measures the linear dichroism of the sample at two peaks near the C 1s absorption edge, demonstrates the continuous polarization rotation capabilities of the undulator.

A beamline has been constructed at Stanford Synchrotron Radiation Laboratory (SSRL) whose radiation source is a multipole permanent magnet '\.\iggler installed in a straight section of the SPEAR 3-3.5 GeV electron storage ring. The wiggler is a hybrid design that utilizes Nd-Fe alloy magnet material combined with Vanadium Permendur poles. It is approximately 2 m long and has 15 full wiggler periods. Its field is regulated by varying its gap height. It has a peak operating field, limited by the electron beam vacuum chamber vertical aperture, of 1.4 T. The beamline consists ofvacuum, safety, and optical components capable oftransporting photons to one hard xray (3-30 keV) end station, with provisions for implementing up to two additional branch lines. The existing hard x~ray branch can be focused by a Pt-coated toroidal mirror with a cutoff energy of approximately 22 keV. The experimental end station is serviced by a Hower-Brown type double crystal monochromator. The wiggler and beamline construction was completed in the fall of 1987 and was operated for a brief period for characterization and experimental use. We present design details and results of the initial characterization studies.

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