Measuring gravity with milligram levitated masses

Gravity differs from all other known fundamental forces since it is best described as a curvature of spacetime. For that reason it remains resistant to unifications with quantum theory. Gravitational interaction is fundamentally weak and becomes prominent only at macroscopic scales. This means, we do not know what happens to gravity in the microscopic regime where quantum effects dominate, and whether quantum coherent effects of gravity become apparent. Levitated mechanical systems of mesoscopic size offer a probe of gravity, while still allowing quantum control over their motional state. This regime opens the possibility of table-top testing of quantum superposition and entanglement in gravitating systems. Here we show gravitational coupling between a levitated sub-millimeter scale magnetic particle inside a type-I superconducting trap and kg source masses, placed approximately half a meter away. Our results extend gravity measurements to low gravitational forces of attonewton and underline the importance of levitated mechanical sensors. Specifically, at a frequency of 26.7 Hz, a mass of 0.4 mg and showing Q-factors in excess of 10$^7$, we obtained a force noise of 0.5 $fN\sqrt{Hz}$ . We simultaneously detect the other 5 rotational and translational degrees of freedom.Comment: 13 pages, with 13 pages supplementary material

Permeability decrease in argillaceous sandstone; experiments and modelling

Core flooding experiments on argillaceous sandstone are carried out showing that for high injection flow rates permeability reduction occurs. The decrease of permeability is a consequence of the migration of insitu particles. Two models are used to simulate the observed phenomena. The so-called network model is able to give insight in the physics behind the particle migration. The other model based on mass balance and constitutive laws is used for quantitative and qualitative comparison with the experiments

De oplossing voor werkloosheid én vervuiling

Een slimme belastinghervorming kan een oplossing bieden voor werkloosheid, vervuiling en een te hoog verbruik van grondstoffen. Wat de Nederlandse overheid in de belastingwetgeving kan aanpassen, zodat de belastingheffing op arbeid minder is en de belastingheffing over vervuiling en grondstoffen meer is

Forkhead box protein P1 as a downstream target of transforming growth factor-beta induces collagen synthesis and correlates with a more stable plaque phenotype

AbstractObjectiveAtherosclerosis is an inflammatory disease, modulated by plaque stabilizing and de-stabilizing cell populations such as infiltrating monocytes and vascular smooth muscle cells (vSMCs). Transcription factors regulating proliferation and differentiation of atherosclerosis relevant cell types are of interest in this context. The forkhead box transcription factor FoxP1 modulates monocyte differentiation. We studied FoxP1 expression in atherosclerotic tissue, correlated FoxP1 expression with plaque characteristics and identified associations between FoxP1 and plaque proteins.Methods116 Atherosclerotic plaques from carotid endarterectomy samples were histologically classified (fibrous, fibroatheromatous, atheromatous) and subjected to semi-quantitative protein analysis. Macrophage, SMC content and intraplaque thrombus amount were determined histologically. FoxP1 expression was investigated by western blotting and immunohistochemistry. In addition FoxP1 was overexpressed in vitro to identify causal relations between FoxP1 and plaque proteins.ResultsFoxP1 expression was observed in SMCs, macrophages, endothelial cells and T-cells within the plaque. High SMC and collagen content correlated with increased FoxP1 isoform (72kD and 95kD) levels. 72kD FoxP1 expression was lower in plaques containing intraplaque thrombus. FoxP1 correlated with active intraplaque TGFβ signaling. In vitro stimulation of SMCs with TGFβ resulted in increased FoxP1 levels. 72kD FoxP1 correlated with expression of pro-fibrotic EGR-1 and increased Col1A1 expression.ConclusionFoxP1 is expressed by different cell types in atherosclerotic lesions and associated with more stable plaque characteristics and intraplaque TGFβ signaling. FoxP1 expression in vitro is induced by TGFβ, resulting in increased collagen and EGR-1 expression, providing a mechanism for the observed association with a more stable plaque phenotype

Oil Prices, Inflation and Interest Rates in a Structural Cointegrated VAR Model for the G-7 Countries

Sharp increases in the price of oil are generally seen as a major contributor to business cycle asymmetries. Moreover, the very recent highs registered in the world oil market are causing concern about possible slowdowns in the economic performance of the most developed countries. While several authors have considered the direct channels of transmission of energy price increases, other authors have argued that the economic downturns arose from the monetary policy response to the inflation presumably caused by oil price increases. In this paper a structural cointegrated VAR model has been considered for the G-7 countries in order to study the direct effects of oil price shocks on output and prices and the reaction of monetary variables to external shocks. Empirical analysis shows that, for most of the countries considered, there seems to be an impact of unexpected oil price shocks on interest rates, suggesting a contractionary monetary policy response directed to fight inflation. In turn, increases in interest rates are transmitted to real economy by reducing output growth and the inflation rate