Comparison of model concepts for nutrient availability and soil acidity in terrestrial ecosystems

STOWA heeft het initiatief genomen om samen met een aantal partijen een klimaatrobuuste Waterwijzer Natuur (WWN) te ontwikkelen. Een instrument dat de effecten van klimaatverandering en het waterbeheer op de terrestrische vegetatie van natuurgebieden dient te kunnen berekenen. Klimaatverandering zal vooral gevolgen voor natuurlijke vegetaties hebben via veranderingen in de waterbalans. Die veranderingen werken namelijk door op de bodemtemperatuur en de hoeveelheid vocht, zuurstof en nutriënten die voor de planten in het wortelmilieu beschikbaar zijn. Klimaatverandering noopt dan ook tot het stellen van enkele essentiële vragen, zoals: Welke maatregelen zijn er nodig om natuurdoelen in de toekomst zeker te stellen? Welke alternatieve doelen kunnen we overwegen als in het verleden vastgestelde natuurdoelen niet meer haalbaar blijken te zijn onder een veranderend klimaat? Waar liggen straks, in het klimaat van de toekomst, de beste kansen voor het creëren van hotspots van biodiversiteit? Dit rapport geeft een overzicht van de overeenkomsten en verschillen van de wijze waarop PROBE (KWR) en VSD+ (WEnR) de nutriëntenbeschikbaarheid en zuurgraad in (half)natuurlijke terrestrische ecosystemen voorspellen in afhankelijkheid van milieu, (vnl. atmosferische depositie), klimaat (vnl. temperatuur en neerslag) en waterbeheerscenario’s

Biomaterials Influence Macrophage-Mesenchymal Stem Cell Interaction In Vitro

Background: Macrophages and mesenchymal stem cells (MSCs) are important cells in wound healing. We hypothesized that the cross-talk between macrophages and adipose tissue-derived MSCs (ASCs) is biomaterial dependent, thereby influencing processes involved in wound healing. Materials and Methods: The effect of macrophages cultured on polypropylene (PP) or polyethylene terephthalate coated with a collagen film (PET/Col) on ASCs in monolayer or on the same material was examined either through conditioned medium (CM) or in a direct coculture. ASC proliferation, collagen production, and gene expression were examined. As comparison, the effect of macrophages stimulated with lipopolysaccharide (LPS) and interferon gamma (IFNγ) [M(LPS/IFNγ)] or interleukin (IL) 4 [M(IL-4)] on ASCs was examined. Results: Macrophage-CM increased collagen deposition, proliferation, and gene expression of MMP1, PLOD2, and PTGS2 in ASCs, irrespective of the material. Culturing ASCs and macrophages in coculture when only macrophages were on the materials induced the same effects on gene expression. When both ASCs and macrophages were cultured on biomaterials, PP induced COL1A1 and MMP1 more than PET/Col. M(LPS/IFNγ) CM increased PLOD2, MMP1, and PTGS2 and decreased TGFB in ASCs more than the M(IL-4) CM. Conclusion: Biomaterials influence wound healing by influencing the interaction between macrophages and ASCs. We provided more insight into the behavior of different cell types during wound healing. This behavior appears to be biomaterial specific depending on which cell type interacts with the biomaterial. As such, the biomaterial will influence tissue regeneration

Novel CNS drug discovery and development approach: model-based integration to predict neuro-pharmacokinetics and pharmacodynamics

Pharmacolog

Prognostic impact of urokinase-type plasminogen activator receptor (uPAR) in cytosols and pellet extracts derived from primary breast tumours

Using a previously developed enzyme-linked immunosorbent assay (ELISA), the levels of the receptor for urokinase-type plasminogen activator (uPAR) were determined in cytosols and corresponding membrane pellets derived from 878 primary breast tumours. The levels of uPAR in the pellet extracts were more than 3-fold higher than those measured in the cytosols (P< 0.001). Moreover, the uPAR levels in the two types of extracts were weakly, though significantly, correlated with each other (rS= 0.20, P< 0.001). In Cox univariate analysis, high cytosolic levels of uPAR were significantly associated with reduced overall survival (OS) and relapse-free survival (RFS). The levels of uPAR in pellet extracts appeared not to be related with patient survival. In multivariate analysis, elevated levels of uPAR measured in cytosols and pellet extracts were found to be independent predictors of poor OS, not RFS. The prediction of poor prognosis on the basis of high uPAR levels emphasizes its important role in plasmin-mediated degradation of extracellular matrix proteins during cancer invasion and metastasis. © 2001 Cancer Research Campaign http://www.bjcancer.co

A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant staphylococcus aureus pandemic

The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones that cause outbreaks and epidemics associated with health care. The most rapidly spreading and tenacious health-care-associated clone in Europe currently is EMRSA-15, which was first detected in the UK in the early 1990s and subsequently spread throughout Europe and beyond. Using phylogenomic methods to analyze the genome sequences for 193 S. aureus isolates, we were able to show that the current pandemic population of EMRSA-15 descends from a health-care-associated MRSA epidemic that spread throughout England in the 1980s, which had itself previously emerged from a primarily community-associated methicillin-sensitive population. The emergence of fluoroquinolone resistance in this EMRSA-15 subclone in the English Midlands during the mid-1980s appears to have played a key role in triggering pandemic spread, and occurred shortly after the first clinical trials of this drug. Genome-based coalescence analysis estimated that the population of this subclone over the last 20 yr has grown four times faster than its progenitor. Using comparative genomic analysis we identified the molecular genetic basis of 99.8% of the antimicrobial resistance phenotypes of the isolates, highlighting the potential of pathogen genome sequencing as a diagnostic tool. We document the genetic changes associated with adaptation to the hospital environment and with increasing drug resistance over time, and how MRSA evolution likely has been influenced by country-specific drug use regimens

Self-Consistent Field study of Polyelectrolyte Brushes

We formulate a self-consistent field theory for polyelectrolyte brushes in the presence of counterions. We numerically solve the self-consistent field equations and study the monomer density profile, the distribution of counterions, and the total charge distribution. We study the scaling relations for the brush height and compare them to the prediction of other theories. We find a weak dependence of the brush height on the grafting density.We fit the counterion distribution outside the brush by the Gouy-Chapman solution for a virtual charged wall. We calculate the amount of counterions outside the brush and find that it saturates as the charge of the polyelectrolytes increases