Effect of external and internal loading on source-sink phosphorus dynamics of river sediment amended with iron-rich glauconite sand.

Glauconite sands (GS) are abundantly available iron (Fe)-rich minerals that are efficient in lowering the release of phosphorus (P) from sediments to the overlying water. Many river sediments are, however, net sinks for P rather than sources and it is unclear if these GS minerals also enhance the P uptake from water. This is because the concentration of Fe(III) minerals at the sediment-water interface (SWI) depends on the redox potential that is affected by physicochemical processes.

Iron rich glauconite sand as an efficient phosphate immobilising agent in river sediments.

The reductive dissolution of iron (Fe) (oxy)hydroxides in sediments releases phosphorus (P) to the overlying water and may lead to eutrophication. Glauconite sands (GS) are rich in Fe and may be used as readily available P sorbents. This study was set up to test effects of dose and type of GS on the P immobilisation in sediments under hypoxic conditions.

Trace element concentrations in mineral phosphate fertilizers used in Europe: A balanced survey.

Mineral phosphate (P) fertilizers contain trace elements (TE) and can be a long-term source of these elements in soil. This study aimed to survey TE concentrations in mineral P fertilizers consumed in 25 of the EU-28 countries plus Norway (EU-28+1), to improve estimates of the EU wide input of TEs in agricultural soils. Different mineral P fertilizers (n = 414) were collected from EU-28+1 with a consumption-balanced sampling strategy.

Soil organic matter affects arsenic and antimony sorption in anaerobic soils.

Soil organic matter (SOM) affects arsenic (As) and antimony (Sb) mobility in soils under waterlogged conditions by acting as an electron donor, by catalyzing redox-cycling through electron shuttling and by acting as a competing ligand. This study was set up to disentangle these different effects of SOM towards As and Sb sorption in anaerobic soils. Nine samples were taken at different depths in an agricultural soil profile to collect samples with a natural SOM gradient (<1-40 g soil organic carbon kg).

Sediment respiration contributes to phosphate release in lowland surface waters.

High phosphate (PO) concentration peaks in lowland rivers occur due to internal loading at low flow rates and low dissolved oxygen (DO) concentrations. However the mechanisms controlling this PO are not fully understood yet. This study was set up to identify additional factors affecting internal P loading, the hypothesis being that sediment respiration varies among sediments and might explain spatial variability in reducing conditions.

Internal Loading and Redox Cycling of Sediment Iron Explain Reactive Phosphorus Concentrations in Lowland Rivers.

The phosphate quality standards in the lowland rivers of Flanders (northern Belgium) are exceeded in over 80% of the sampling sites. The factors affecting the molybdate reactive P (MRP) in these waters were analyzed using the data of the past decade (>200 000 observations). The average MRP concentration in summer exceeds that winter by factor 3.

Phosphorus losses from agricultural land to natural waters are reduced by immobilization in iron-rich sediments of drainage ditches.

Redox reactions involving iron (Fe) strongly affect the mobility of phosphorus (P) and its migration from agricultural land to freshwater. We studied the transfer of P from groundwater to open drainage ditches in an area where, due to Fe(II) rich groundwater, the sediments of these ditches contain accumulated Fe oxyhydroxides. The average P concentrations in the groundwater feeding two out of three studied drainage ditches exceeded environmental limits for freshwaters by factors 11 and 16, but after passing through the Fe-rich sediments, the P concentrations in the ditch water were below these limits.

Replication characteristics of porcine reproductive and respiratory syndrome virus (PRRSV) European subtype 1 (Lelystad) and subtype 3 (Lena) strains in nasal mucosa and cells of the monocytic lineage: indications for the use of new receptors of PRRSV (Lena).

Recently, it has been demonstrated that subtype 3 strains of European type porcine reproductive and respiratory syndrome virus (PRRSV) are more virulent/pathogenic than subtype 1 strains. This points to differences in the pathogenesis. In the present study, a new polarized nasal mucosa explant system was used to study the invasion of the low virulent subtype 1 PRRSV strain Lelystad (LV) and the highly virulent subtype 3 PRRSV strain Lena at the portal of entry.

Porcine, murine and human sialoadhesin (Sn/Siglec-1/CD169): portals for porcine reproductive and respiratory syndrome virus entry into target cells.

Porcine sialoadhesin (pSn; a sialic acid-binding lectin) and porcine CD163 (pCD163) are molecules that facilitate infectious entry of porcine reproductive and respiratory syndrome virus (PRRSV) into alveolar macrophages. In this study, it was shown that murine Sn (mSn) and human Sn (hSn), like pSn, can promote PRRSV infection of pCD163-expressing cells. Intact sialic acid-binding domains are crucial, since non-sialic acid-binding mutants of pSn, mSn and hSn did not promote infection.

Porcine reproductive and respiratory syndrome virus (PRRSV)-specific mAbs: supporting diagnostics and providing new insights into the antigenic properties of the virus.

The porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important viral pathogens in the swine industry. Despite great efforts of pig holders, veterinarians, researchers and vaccine developers, the virus still causes major production losses. It is clear that efficient and correct monitoring and rational development of vaccines are crucial in the combat against this pathogen.