30 research outputs found
Continuous population-level monitoring of SARS-CoV-2 seroprevalence in a large European metropolitan region.
Effective public health measures against SARS-CoV-2 require granular knowledge of population-level immune responses. We developed a Tripartite Automated Blood Immunoassay (TRABI) to assess the IgG response against three SARS-CoV-2 proteins. We used TRABI for continuous seromonitoring of hospital patients and blood donors (n = 72'250) in the canton of Zurich from December 2019 to December 2020 (pre-vaccine period). We found that antibodies waned with a half-life of 75 days, whereas the cumulative incidence rose from 2.3% in June 2020 to 12.2% in mid-December 2020. A follow-up health survey indicated that about 10% of patients infected with wildtype SARS-CoV-2 sustained some symptoms at least twelve months post COVID-19. Crucially, we found no evidence of a difference in long-term complications between those whose infection was symptomatic and those with asymptomatic acute infection. The cohort of asymptomatic SARS-CoV-2-infected subjects represents a resource for the study of chronic and possibly unexpected sequelae
Characterization of zinc in contaminated soils: complementary insights from isotopic exchange, batch extractions and XAFS spectroscopy
Isotopic exchange (IE) of trace metals is an established method for characterizing metal reactivity in soils, but it is still unclear which metal species are isotopically exchangeable. In this study, we used IE to quantify ‘labile’ zinc (Zn) in 51 contaminated soils that were previously studied by Zn K-edge X-ray absorption fine
structure (XAFS) spectroscopy and sequential extraction (SE). All soils had been contaminated by runoff water from 17- to 74-year-old galvanized power-line towers.
They covered a wide range in pH (4.0–7.7), organic carbon (0.9–10.2%), clay (3.8– 45.1%) and Zn concentrations (251–30 090 mg kg−1). Isotopic exchange was
also performed on selected Zn minerals used as references for linear combination fitting of XAFS spectra. The isotopically exchangeable fraction (%E) of Zn generally decreased with increasing pH, but small %E values were also observed for acidic soils with a large fraction of Zn in hydroxy-interlayered minerals (Zn-HIM). The fraction of Zn identified by XAFS spectroscopy as (tetrahedrally and octahedrally coordinated) ‘sorbed Zn’ agreed reasonably well with the isotopically exchangeable fraction but was in many cases larger than the % E, indicating that some ‘sorbed Zn’ may be isotopically non-exchangeable, such as Zn sorbed in micropores of Fe oxyhydroxides. Zinc identified by XAFS spectroscopy as Zn precipitates (Zn phyllosilicates, Zn-layered double hydroxide (Zn-LDH) or hydrozincite) or as Zn-HI
M was largely isotopically non-exchangeable (‘non-labile’). Comparison between IE and extraction results suggested that the isotopically exchangeable Zn was mainly extracted in the first two fractions of the SE. However, non-labile Zn was also extracted in these first two fractions for some soils, including a hydrozincite-containing soil. Despite the presence of Zn-LDH and/or Zn phyllosilicates in almost all soils, the Zn concentrations in solution and labile Zn increased with increasing
soil total Zn at a given pH, which contradicts the concept of precipitation control by a single phase. Solution Zn was well predicted from the labile Zn following a sorption model.F. Degryse, A. Voegelin, O. Jacquat, R. Kretschmar and E. Smolder
Origin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy: evidence from Zn speciation and distribution
ISSN:1661-8734ISSN:1661-872
Origin of high Zn contents in Jurassic limestone of the Jura mountain range and the Burgundy: evidence from Zn speciation and distribution
Abstract In order to better understand the origin and enrichment mechanisms leading to elevated Zn concentrations in Jurassic limestone of the Jura mountain range (JMR) and the Burgundy (B), we investigated four locations of Bajocian age (JMR: Lausen-Schleifenberg, Gurnigel; B: Vergisson-Davayé, Lucy-le-Bois) and two locations of Oxfordian age (JMR: Dornach, Pichoux) for their Zn distribution and speciation. Measurements of the acid-extractable and bulk Zn contents showed that Zn is stratigraphically and spatially heterogeneously distributed, in association with permeable carbonate levels. Up to 3,580 and 207 mg/kg Zn was detected in Bajocian and Oxfordian limestone, respectively, with numerous limestone samples having Zn contents above 50 mg/kg. Using X-ray absorption near edge structure spectroscopy and micro-X-ray fluorescence spectrometry, the speciation and microscale distribution of Zn was investigated for selected limestone samples. In Bajocian limestone sphalerite and/or Zn-substituted goethite and a minor fraction of Zn-bearing carbonates were identified. In contrast, Zn-bearing carbonates (Zn-substituted calcite and hydrozincite) were accounting for most of the total Zn in Oxfordian limestone. The micro-scale distribution of Zn for Bajocian and Oxfordian limestone was however similar with localized Zn-rich zones in the limestone cement and at the rim of oolites. The stratigraphic sporadicity and microscale heterogeneity of the Zn distribution together with the Zn speciation results point to a hydrothermal origin of Zn. Occurence of Zn-goethite is probably linked to the oxidative transformation of framboidal pyrite and hydrothermal sphalerite in contact with meteoritic waters. Difference in speciation between Bajocian limestone and Oxfordian limestone may be related to differences in rock permeability Geosci (2011) 104:409-424 DOI 10.1007 and/or to various hydrothermal events. Isotopic dating of the different mineralizations will be needed to decipher differences in Zn speciation and the precise chronology of hydrothermal episodes
Changes in Zinc Speciation with Mine Tailings Acidification in a Semiarid Weathering Environment
New data about the consumption of fish from the Alsace Region, France
International audienceThis study provides an overview of 11 archaeological sites that yielded fish boneremains from the Roman period through medieval to modern contexts. It bringsnew knowledge about the consumption of fish for the Alsace region. Although thenumbers of remains vary greatly, some diachronic comparisons are possible. Themajority of the species represented in the assemblages from the inland sites sampledwere freshwater fishes, together with a few migratory fishes. Most individuals weresmall‐sized fishes, which may explain the type of structure analysed, for instance,latrines. Two wels catfish vertebrae indicate the presence of this species in France.European marine fishes such as cod and flatfish are very rare, and the importationof marine fish began more recently. However, some herring bones found in theRoman and early medieval period make a straightforward interpretation moredifficult