Most SARS-CoV-2 antibody assays cannot distinguish between antibodies that developed after natural infection and those that developed after vaccination. We assessed the accuracy of a ...nucleocapsid-containing assay in identifying natural infection among vaccinated individuals. A longitudinal cohort composed of health care workers in the Minneapolis/St. Paul area was enrolled. Two rounds of seroprevalence studies separated by 1 month were conducted from November 2020 to January 2021 among 81 participants. Capillary blood from rounds 1 and 2 was tested for IgG antibodies against spike proteins by enzyme-linked immunosorbent assay (spike-only assay). During round 2, IgGs reactive to SARS-CoV-2 nucleocapsid protein (nucleocapsid-containing assay) were assessed. Vaccination status at round 2 was determined by self-report. Area under the curve was computed to determine the discriminatory ability of the nucleocapsid-containing assay for identification of recent infection. Participants had a mean age of 40 years (range, 23 to 66 years); 83% were female. Round 1 seroprevalence was 9.5%. Before round 2 testing, 46% reported vaccination. Among those not recently infected, in comparing vaccinated vs unvaccinated individuals, elevated levels of spike 1 (P<.001) and spike 2 (P=.01) were observed, whereas nucleocapsid levels were not statistically significantly different (P=.90). Among all participants, nucleocapsid response predicted recent infection with an area under the curve of 0.93 (95% CI, 0.88 to 0.99). Among individuals vaccinated more than 10 days before antibody testing, the specificity of the nucleocapsid-containing assay was 92%, whereas the specificity of the spike-only assay was 0%. An IgG assay identifying reactivity to nucleocapsid protein is an accurate predictor of natural infection among a partially vaccinated population, whereas a spike-only assay performed poorly.
Integrated reference electrodes allow to deconvolute voltage contributions of anode and cathode and contribute to a better understanding of CO2 electrolyzers. However, in zero-gap cell ...configurations, this integration can be challenging and obtaining error-free data with such a setup is a non-trivial task. This study compares five different methods to integrate a reference electrode into an alkaline zero-gap CO2 electrolysis cell. Sources of error and measures to circumvent them are investigated and finite-element simulation is used to gain a better understanding of observed effects. Placing a reference electrode into the inactive area of the cell is found to be a reliable method, as long as the placement of electrodes is sufficiently controlled. Sandwiching a wire quasi-reference electrode between two membranes is especially useful for electrochemical impedance spectroscopy; however, it can affect the overall cell performance. Contacting the catalyst layer from the backside with a salt-bridge is promising for localized measurements if sufficient reproducibility can be ensured.Integrated reference electrodes allow to deconvolute voltage contributions of anode and cathode and contribute to a better understanding of CO2 electrolyzers. However, in zero-gap cell configurations, this integration can be challenging and obtaining error-free data with such a setup is a non-trivial task. This study compares five different methods to integrate a reference electrode into an alkaline zero-gap CO2 electrolysis cell. Sources of error and measures to circumvent them are investigated and finite-element simulation is used to gain a better understanding of observed effects. Placing a reference electrode into the inactive area of the cell is found to be a reliable method, as long as the placement of electrodes is sufficiently controlled. Sandwiching a wire quasi-reference electrode between two membranes is especially useful for electrochemical impedance spectroscopy; however, it can affect the overall cell performance. Contacting the catalyst layer from the backside with a salt-bridge is promising for localized measurements if sufficient reproducibility can be ensured.
Mollusca are widely used for deriving concepts on deep-sea biology and biodiversity, yet abyssal collections are limited to only a few regions of the world ocean and biased toward the northern ...Atlantic. The present study compares gastropod molluscs sampled along a transect through the southern Atlantic from the equator to Antarctica. The DIVA I and II expeditions concentrated on the hardly explored Guinea, Angola, and Cape Basins. Of the 145 deep-sea deployments (5025-5656
m depth) analyzed to date, 20 have yielded 68 specimens of benthic gastropods, representing 27 species. Only five abyssal species were previously known, four of them from the northern Atlantic deep sea; the remainder appear to be undescribed. Interestingly, there is no faunal overlap with the nearby Antarctic deep-sea. Most of these DIVA species (63%) are represented by single individuals, or limited to one or two stations. The rarity (i.e. 0.55 specimens m
−2 calculated from quantitative corers) and still undetectable patchiness of southeastern Atlantic abyssal gastropods may indicate “source-sink” dynamics, but comparison is needed with thus far hardly explored regional bathyal faunas. The BRENKE-epibenthic sledge (EBS) may be efficient at surveying the abyssal gastropod species richness, but is shown to drastically underestimate true abundances. Low diversity values throughout the three southern Atlantic ocean basins do further challenge earlier estimates of a hyperdiverse global abyssal macrofauna. Comparative EBS data available from the southern hemisphere indicate a gradient from the equatorial Guinea Basin towards higher gastropod abundances and diversity in Antarctica. This is in clear contrast to the paradigm of a globally strongly decreasing marine diversity from lower to higher latitudes, highlighting the importance of further exploring the southern fauna from the tropics to Antarctica.
After invasion via M cells enteropathogenic Yersinia enterocolitica subsequently establish an infection at three different sites: (i) Peyer's patches (PP), (ii) mesenteric lymph nodes (MLN), and ...after systemic dissemination in (iii) spleen, liver and lung. In order to characterize protective properties of intestinal T cells at the different sites of Y. enterocolitica infection, PP and MLN T cells were isolated from Y. enterocolitica‐infected C57Bl/6 mice and Yersinia‐specific T cell lines were generated. These T cells exhibited the phenotype of CD4 Th1 cells. The adoptive transfer of Yersinia‐specific Th1 cells from PP and MLN conferred protection against a lethal orogastric inoculum with Y. enterocolitica as revealed by survival post‐infection. However, determination of bacterial counts in infected organs revealed that the transfer of PP T cells conferred protection in spleen but not in MLN and PP, whereas the transfer of T cells from MLN reduced bacterial counts in both spleen and MLN but not in PP. To elucidate the different protection pattern we wanted to track the transferred cells in vivo. For this purpose the cells were labelled with the stable green fluorescent cell linker PKH2‐GL prior to the adoptive transfer. In vivo tracking of these cells revealed that the distribution pattern of transferred T cells in spleen, MLN and PP correlated closely with the protection pattern observed after Yersinia infection. Thus, most cells were recovered from the spleen, while only few cells were recovered from MLN and PP. In keeping with these results a rapid and significant increase in interferon‐gamma (IFN‐γ) production in the spleen of mice after adoptive transfer of T cell lines was observed. Taken together, the present results demonstrate that intestinal CD4 Th1 cells from PP and MLN may be involved in the defence against Y. enterocolitica at different sites of the infection, and that PKH2‐GL labelling is a suitable tool to characterize T cell functions in vivo.
The prediction of methane emissions from high-latitude wetlands is important given concerns about their sensitivity to a warming climate. As a basis for the prediction of wetland methane emissions at ...regional scales, we coupled the variable infiltration capacity macroscale hydrological model (VIC) with the biosphere–energy-transfer–hydrology terrestrial ecosystem model (BETHY) and a wetland methane emissions model to make large-scale estimates of methane emissions as a function of soil temperature, water table depth, and net primary productivity (NPP), with a parameterization of the sub-grid heterogeneity of the water table depth based on TOPMODEL. We simulated the methane emissions from a 100km × 100km region of western Siberia surrounding the Bakchar Bog, for a retrospective baseline period of 1980–1999 and have evaluated their sensitivity to increases in temperature of 0–5 °C and increases in precipitation of 0–15%. The interactions of temperature and precipitation, through their effects on the water table depth, played an important role in determining methane emissions from these wetlands. The balance between these effects varied spatially, and their net effect depended in part on sub-grid topographic heterogeneity. Higher temperatures alone increased methane production in saturated areas, but caused those saturated areas to shrink in extent, resulting in a net reduction in methane emissions. Higher precipitation alone raised water tables and expanded the saturated area, resulting in a net increase in methane emissions. Combining a temperature increase of 3 °C and an increase of 10% in precipitation to represent climate conditions that may pertain in western Siberia at the end of this century resulted in roughly a doubling in annual emissions.
Pressure ulcers (PrUs) affect approximately 2.5 million patients and account for 60,000 deaths annually. They are associated with an additional annual cost of $43,000 per related hospital stay and a ...total cost to the US health care system as high as $25 billion. Despite the implementation of national and international PrU prevention guidelines and toolkits, rates of facility‐acquired PrU s and PrUs in people with spinal cord injury are still high. A new paradigm is needed that distinguishes between prevention and treatment research methods and includes not only the causative factors of pressure and tissue deformation but also patient‐specific anatomical differences and the concomitant biological cellular processes, including reperfusion injury, toxic metabolites, ischemia, cell distortion, impaired lymphatic drainage, and impaired interstitial fluid flow that compound existing tissue damage. The purpose of this article is to summarize the highlights from the first annual Pressure Ulcer Summit held February 9–10, 2018 in Atlanta, Georgia (sponsored by the Association for the Advancement of Wound Care in partnership with multiple professional organizations). This international, interdisciplinary summit brought together key stakeholders in wound care and PrU prevention and management to highlight advances in pathophysiology of pressure‐induced tissue damage; explore challenges in current terminologies, documentation, and data collection; describe innovations in clinical care; and identify research opportunities to advance the science of PrU prevention and management.
Snow and ice melt processes on the Greenland Ice Sheet are a key in Earth's energy balance and are acutely sensitive to climate change. Melting dynamics are directly related to a decrease in surface ...albedo, amongst others caused by the accumulation of light‐absorbing particles (LAPs). Featuring unique spectral patterns, these accumulations can be mapped and quantified by imaging spectroscopy. We present first results for the retrieval of glacier ice properties from the spaceborne PRISMA imaging spectrometer by applying a recently developed simultaneous inversion of atmospheric and surface state using optimal estimation. The image analyzed in this study was acquired over the South‐West margin of the Greenland Ice Sheet in late August 2020. The area is characterized by patterns of both clean and dark ice associated with a high amount of LAPs deposited on the surface. We present retrieval maps and uncertainties for grain size, liquid water, and algae concentration, as well as estimated reflectance spectra for different surface properties. We then show the feasibility of using imaging spectroscopy to interpret multiband sensor data to achieve high accuracy, frequently repeated observations of changing snow and ice conditions. For example, the impurity index calculated from multiband Sentinel‐3 Ocean and Land Colour Instrument measurements is dependent on dust particles, but we show that algae concentration alone can be predicted from this data with less than 20% uncertainty. Our study evidences that present and upcoming orbital imaging spectroscopy missions such as PRISMA, Environmental Mapping and Analysis Program, Copernicus Hyperspectral Imaging Mission, and the Surface Biology and Geology designated observable, can significantly support research of melting ice sheets.
Plain Language Summary
The Greenland Ice Sheet plays a key role in climate change since increased melting over the past decades significantly contributes to global sea level rise and the associated socioeconomic consequences. Melting dynamics are controlled by the amount of solar radiation absorbed by the surface. This amount increases when ice gets darker, which is mainly caused by small particles such as algae and dust accumulating on the surface and reducing its brightness. Therefore, the detection of these particles is essential for predicting melt processes on the Greenland Ice Sheet. A new generation of Earth observation satellites provides the technical prerequisites to achieve this objective. In this study, we present first results from the recently started PRISMA satellite mission using a data set recorded over the Greenland Ice Sheet in late August 2020. We apply a new method to estimate the size of ice crystals, liquid water content, and algae concentration on the surface demonstrating the potential of the new missions to detect and quantify snow and ice properties with a high accuracy. Finally, we evidence that a combination of novel future satellite observations and existing data records from other instruments can decisively support research of melting ice sheets.
Key Points
It is the first time that PRISMA imaging spectroscopy data are used for studying the cryosphere on the Greenland Ice Sheet
We present an algorithm to detect and quantify patterns of light‐absorbing particles accumulated on the ice surface in the so‐called dark zone
Global VSWIR imaging spectrometers open new possibilities of producing multi‐year time series of snow and ice properties mapping
We investigated magnesium ferrite MgFe2O4 nanoparticles synthesized by the sol-gel method followed by heat treatment at distinct temperatures. Specifically, we evaluated the influence of the heat ...treatment on the structural, magnetic, electrical, and dielectric properties of particles with dimensions of nm. Then, we brought a route, a synthesis method followed by heat treatment, that provide us the high control of the particle composition and particle size. X-ray diffraction analysis and transmission electron microscopy images revealed the formation of pure magnesium ferrite nanoparticles, with increasing average particle diameter with treatment temperature. The modifications of the structural parameters were correlated with the cation distribution between the tetrahedral (A) and octahedral B sites of the magnesium ferrite, which evolves with the increase of the Mg2+ ions at the B site as the heat treatment temperature is raised. The changes in the structural features induced by heat treatment at distinct temperatures led to modifications in the magnetic and dielectric properties of the ferrites. Magnetic characterization disclosed a dependence of the magnetic parameters with the treatment temperature. On the electric features, a decrease in the electrical resistivity with the treatment temperature was found, a fact primarily due to the increase of the grain size and the cation distribution of Mg and Fe. Regarding the dielectric characteristics, we disclosed low values for the dielectric constant and dielectric loss factor for the whole range of frequencies (0.1 up to 1.5 GHz), despite the dependence with the heat-treatment temperature and evolution with probe frequency. Through Mössbauer experiments, we elucidated the conduction mechanisms in our MgFe2O4 ferrite. Our results demonstrate that the structural, magnetic, electrical, and dielectric properties of MgFe2O4 nanoparticles can be tuned by the synthesis method followed by heat treatment. All these features place the magnesium ferrite MgFe2O4 nanoparticles, synthesized by sol-gel followed by heat treatment at distinct temperatures, suitable for sensor elements in technological devices and microwave applications.
•Sol-gel method followed by heat treatment is an e_cient route for the synthesis of MgFe2O4 nanoparticles.•A route that provide us the high control of the particle composition and particle size.•Tuning the structural, magnetic, electrical and dielectric properties of MgFe2O4 nanoparticles.•MgFe2O4 nanoparticles suitable for sensor elements in technological devices and microwave applications.
It was the purpose of the present study to validate administrative claims codes for idiopathic thrombotic thrombocytopenic purpura (TTP) in a commercially-insured US population. Patients with at ...least one medical claim with ICD-9 code 446.6X between 1/1/2001 and 5/31/2008 were identified in the HealthCore Integrated Research Database (HIRD). A chart abstraction form was developed to enable case determination for patients identified by the claims code. Two clinical experts, not involved in the design of the study, reviewed the abstracted medical record data and determined whether definite evidence supporting the diagnosis of TTP was present. The positive predictive value (PPV) of the claims coding algorithm for cases assessed by both reviewers was computed. The claims algorithm was further refined and the PPV of the refined algorithm was computed. One hundred eighty-nine abstracted charts were reviewed by two clinical experts; 86 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 45.5% 86/189; 95% confidence interval (CI), 38.3-52.9%). Refinement of the claims algorithm first included the use of plasma exchange treatment, resulting in 103 potential cases, of which 67 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 65.0%; 95% CI, 55.0-74.2%). Further refinement of the claims algorithm ruled out alternative diagnoses that may mimic TTP; 34 were assessed to have definite evidence supporting the diagnosis of TTP (PPV 72.3% 34/47; 95% CI, 57.4-84.4%).Our findings demonstrate the difficulty of confirming the diagnosis of rare disorders that lack definite diagnostic criteria, and indicate that more complex claims coding algorithms are necessary for identifying these disorders.
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