147 research outputs found
Low anti-staphylococcal IgG responses in granulomatosis with polyangiitis patients despite long-term Staphylococcus aureus exposure
Chronic nasal carriage of the bacterium Staphylococcus aureus in patients with the autoimmune disease granulomatosis with polyangiitis (GPA) is a risk factor for disease relapse. To date, it was neither known whether GPA patients show similar humoral immune responses to S. aureus as healthy carriers, nor whether specific S. aureus types are associated with GPA. Therefore, this study was aimed at assessing humoral immune responses of GPA patients against S. aureus antigens in relation to the genetic diversity of their nasal S. aureus isolates. A retrospective cohort study was conducted, including 85 GPA patients and 18 healthy controls (HC). Humoral immune responses against S. aureus were investigated by determining serum IgG levels against 59 S. aureus antigens. Unexpectedly, patient sera contained lower anti-staphylococcal IgG levels than sera from HC, regardless of the patients' treatment, while total IgG levels were similar or higher. Furthermore, 210 S. aureus isolates obtained from GPA patients were characterized by different typing approaches. This showed that the S. aureus population of GPA patients is highly diverse and mirrors the general S. aureus population. Our combined findings imply that GPA patients are less capable of mounting a potentially protective antibody response to S. aureus than healthy individuals
Thorium speciation in seawater
Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Chemistry 100 (2006): 250-268, doi:10.1016/j.marchem.2005.10.024.Since the 1960âs, thorium isotopes occupy a special place in the oceanographerâs toolbox as
tracers for determining rates and mechanisms of oceanic scavenging, particle dynamics, and
carbon fluxes. Due to their unique and constant production rates from soluble parent nuclides of
uranium and radium, their disequilibrium can be used to calculate rates and time scales of
sinking particles. In addition, by ratio-ing particulate 234Th (as well, in principle, other Thnuclides)
to carbon (and other elements), and linking this ratio to the parent-daughter
disequilibrium in the water column, it is possible to calculate fluxes of carbon and other
elements. Most of these applications are possible with little knowledge of the dissolved chemical
properties of thorium, other than its oxidation state (IV) and tendency to strongly sorb to
surfaces, i.e., its âparticle- or surface-activityâ. However, the use of any tracer is hindered by a
lack of knowledge of its chemical properties. Recent observations in the variability of carbon to
234Th ratios in different particle types, as well as of associations of Th(IV) with various marine
organic biomolecules has led to the need for a review of current knowledge and what future
endeavors should be taken to understand the marine chemistry of thorium.The writing of this paper was supported, in parts by NSF (OCE-0351559; OCE-0350758, and
OCE 0354757)
Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients
The GEOTRACES Intermediate Data Product 2014
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes
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