A two-species model of a two-dimensional sandpile surface: a case of asymptotic roughening

We present and analyze a model of an evolving sandpile surface in (2 + 1) dimensions where the dynamics of mobile grains ({\rho}(x, t)) and immobile clusters (h(x, t)) are coupled. Our coupling models the situation where the sandpile is flat on average, so that there is no bias due to gravity. We find anomalous scaling: the expected logarithmic smoothing at short length and time scales gives way to roughening in the asymptotic limit, where novel and non-trivial exponents are found.Comment: 7 Pages, 6 Figures; Granular Matter, 2012 (Online

First- and second-order phase transitions in a driven lattice gas with nearest-neighbor exclusion

A lattice gas with infinite repulsion between particles separated by $\leq 1$ lattice spacing, and nearest-neighbor hopping dynamics, is subject to a drive favoring movement along one axis of the square lattice. The equilibrium (zero drive) transition to a phase with sublattice ordering, known to be continuous, shifts to lower density, and becomes discontinuous for large bias. In the ordered nonequilibrium steady state, both the particle and order-parameter densities are nonuniform, with a large fraction of the particles occupying a jammed strip oriented along the drive. The relaxation exhibits features reminiscent of models of granular and glassy materials.Comment: 8 pages, 5 figures; results due to bad random number generator corrected; significantly revised conclusion

Analysis of GPRC6A variants in different pancreatitis etiologies

The G-protein-coupled receptor Class C Group 6 Member A (GPRC6A) is activated by multiple ligands and is important for the regulation of calcium homeostasis. Extracellular calcium is capable to increase NLRP3 inflammasome activity of the innate immune system and deletion of this proinflammatory pathway mitigated pancreatitis severity in vivo. As such this pathway and the GPRC6A receptor is a reasonable candidate gene for pancreatitis. Here we investigated the prevalence of sequence variants in the GPRC6A locus in different pancreatitis aetiologies.We selected 6 tagging SNPs with the SNPinfo LD TAG SNP Selection tool and the functional relevant SNP rs6907580 for genotyping. Cohorts from Germany, further European countries and China with up to 1,124 patients and 1,999 controls were screened for single SNPs with melting curve analysis.We identified an association of rs1606365(G) with alcoholic chronic pancreatitis in a German (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.65-0.89, p = 8 × 10-5) and a Chinese cohort (OR 0.78, 95% CI 0.64-0.96, p = 0.02). However, this association was not replicated in a combined cohort of European patients (OR 1.18, 95% CI 0.99-1.41, p = 0.07). Finally, no association was found with acute and non-alcoholic chronic pancreatitis.Our results support a potential role of calcium sensing receptors and inflammasome activation in alcoholic chronic pancreatitis development. As the functional consequence of the associated variant is unclear, further investigations might elucidate the relevant mechanisms

The seasonal variation in soil water acid neutralizing capacity in peaty podzols in mid-Wales

Between 1985 and 1990, bulk precipitation and soil solution from the organic (Oh) and mineral (Bs) horizons of a well developed podzol were regularly sampled at a moorland catchment in Mid-Wales. Samples were analysed for pH, major cations, major anions, and dissolved organic carbon (DOC). Acid neutralizing capacity (ANC) was estimated by the charge balance method. Average monthly ANC of soil solutions from the Oh horizon varied seasonally, with a maximum in July and a minimum in February. In contrast, H+ concentrations varied little. Solute deposition, dominated by sodium and chloride, also varied seasonally with a winter maximum, which is reflected in the soil solution chemical composition. In the Oh horizon during winter, the increase in base cation (Na) concentrations led to release of H+ through ion exchange. ANC declined in the absence of any buffering mechanism. In summer, the depletion of exchangeable acidity that occurred in winter, was replenished by H+ produced by the dissociation of organic acids. During this period, organic anions contribute to an increase in ANC, while H+ concentrations remained similar to those in winter. These processes probably influenced the acidity and ANC of Bs horizon soil solutions but to a lesser extent than in the Oh horizon. Other mechanisms such as weathering and ion exchange involving H+ and Al may buffer solution acidity in the mineral soil

A framework to identify enabling and urgent actions for the 2020 Aichi Targets

In 2010, the parties of the Convention on Biological Diversity (CBD) adopted the Strategic Plan for Biodiversity 2011–2020 with the mission of halting biodiversity loss and enhance the benefits it provides to people. The 20 Aichi Biodiversity Targets (Aichi Targets), which are included in the Strategic Plan, are organized under five Strategic Goals, and provide coherent guidance on how to achieve it. Halfway through the Strategic Plan, it is time to prioritize actions in order to achieve the best possible outcomes for the Aichi Targets in 2020. Actions to achieve one target may influence other targets (downstream interactions);in turn a target may be influenced by actions taken to attain other targets (upstream interactions). We explore the interactions among targets and the time-lags between implemented measures and desired outcomes to develop a framework that can reduce the overall burden associated with the implementation of the Strategic Plan. We identified the targets addressing the underlying drivers of biodiversity loss and the targets aimed at enhancing the implementation of the Strategic Plan as having the highest level of downstream interactions. Targets aimed at improving the status of biodiversity and safeguarding ecosystems followed by targets aimed at reducing the direct pressures on biodiversity and enhancing the benefits to all from biodiversity and ecosystem services, were identified as having the highest levels of upstream interactions. Perhaps one of the most challenging aspects of the Strategic Plan is the need to balance actions for its long-term sustainability with the need for urgent actions to halt biodiversity loss

EPCR-PAR1 biased signaling regulates perfusion recovery and neovascularization in peripheral ischemia

Blood clot formation initiates ischemic events, but coagulation roles during postischemic tissue repair are poorly understood. The endothelial protein C receptor (EPCR) regulates coagulation, as well as immune and vascular signaling, by protease activated receptors (PARs). Here, we show that endothelial EPCR-PAR1 signaling supports reperfusion and neovascularization in hindlimb ischemia in mice. Whereas deletion of PAR2 or PAR4 did not impair angiogenesis, EPCR and PAR1 deficiency or PAR1 resistance to cleavage by activated protein C caused markedly reduced postischemic reperfusion in vivo and angiogenesis in vitro. These findings were corroborated by biased PAR1 agonism in isolated primary endothelial cells. Loss of EPCR-PAR1 signaling upregulated hemoglobin expression and reduced endothelial nitric oxide (NO) bioavailability. Defective angiogenic sprouting was rescued by the NO donor DETA-NO, whereas NO scavenging increased hemoglobin and mesenchymal marker expression in human and mouse endothelial cells. Vascular specimens from patients with ischemic peripheral artery disease exhibited increased hemoglobin expression, and soluble EPCR and NO levels were reduced in plasma. Our data implicate endothelial EPCR-PAR1 signaling in the hypoxic response of endothelial cells and identify suppression of hemoglobin expression as an unexpected link between coagulation signaling, preservation of endothelial cell NO bioavailability, support of neovascularization, and prevention of fibrosis

The Influence of IFN-α on Blood Plasmacytoid Dendritic Cell in Chronic Myeloid Leukaemia

OBJECTIVE To study the mechanism of IFN on CML. METHODS Samples of 15 CML patients and 10 healthy controls were studied. The flow cytometry was performed to identify circulating pDCs. The concentration of IFN- α in serum and that in the supernatant of peripheral blood mononuclear cells (PBMCs) cultured after stimulation with CpG ODN2216 were examined both in CML patients and in the healthy controlsRESULTS There was significant reduction in the number of circulating pDCs, serum concentration of IFN- α and the capacity of IFN-α producing PBMCs in CML patients compared with those in healthy control individuals (P < 0.001). After the active treatment with IFN-α and hydroxyurea, the quantity and function of pDCs were increased in stabilized patients, especially the function of pDCs in 2 patients achieving major cytogenetic response (MCR). The proportion and function of pDCs and the serum levels of IFN were inversely correlated with both WBC and age of the patients with CML, and positively correlated with the state of the illness.CONCLUSION CML patients had a reduced number and dysfunction of circulating pDCs. The active treatment with IFN in CML patients may be related to the restoration of pDCs