483 research outputs found
Kraichnan-Leith-Batchelor similarity theory and two-dimensional inverse cascades
We study the scaling properties and Kraichnan-Leith-Batchelor (KLB) theory of forced inverse cascades in generalized two-dimensional (2D) fluids (-turbulence models) simulated at resolution . We consider (surface quasigeostrophic flow), (2D vorticity dynamics) and . The forcing scale is well-resolved, a direct cascade is present and there is no large-scale dissipation. Coherent vortices spanning a range of sizes, most larger than the forcing scale, are present for both and . The active scalar field for contains comparatively few and small vortices. The energy spectral slopes in the inverse cascade are steeper than the KLB prediction in all three systems. Since we stop the simulations well before the cascades have reached the domain scale, vortex formation and spectral steepening are not due to condensation effects; nor are they caused by large-scale dissipation, which is absent. One- and two-point pdfs, hyperflatness factors and structure functions indicate that the inverse cascades are intermittent and non-Gaussian over much of the inertial range for and , while the inverse cascade is much closer to Gaussian and non-intermittent. For the steep spectrum is close to that associated with enstrophy equipartition. Continuous wavelet analysis shows approximate KLB scaling () and () in the interstitial regions between the coherent vortices. Our results demonstrate that coherent vortex formation ( and ) and non-realizability () cause 2D inverse cascades to deviate from the KLB predictions, but that the flow between the vortices exhibits KLB scaling and non-intermittent statistics for and . The results will appear in \cite{BurgessEA2015}, which has been accepted to the \emph{Journal of Fluid Mechanics}
Soluble and multivalent Jag1 DNA origami nanopatterns activate Notch without pulling force
Funding Information: The authors would like to acknowledge support from the NIH grant number R35GM133482 for V.C.L., the Knut and Alice Wallenberg Foundation (Grants KAW 2017.0114 for B.H. and A.I.T. and KAW 2017.0276 for B.H.), from the European Research Council ERC for B.H. (Acronym: Cell Track GA No. 724872) and A.I.T (Acronym: MechComm GA No. 617711), and from the Swedish Research Council for B.H. (grant no. 2019-01474) and from the Göran Gustafsson Foundation for B.H. And from the Academy of Finland for B.S. (grant no. 341908). lt-NES samples were obtained from, and initial culture protocols was made possible with the help of Anna Falk’s team and the iPS Core facility at Karolinska Institutet. Part of this work was performed at the Karolinska Institutet/SciLifeLab Protein Science Core Facility (PSF). Part of this work was performed at the Karolinska Institutet Biomedicum Imaging Core (BIC). EM data was collected at the Karolinska Institutet 3D-EM facility. Publisher Copyright: © 2024, The Author(s).The Notch signaling pathway has fundamental roles in embryonic development and in the nervous system. The current model of receptor activation involves initiation via a force-induced conformational change. Here, we define conditions that reveal pulling force-independent Notch activation using soluble multivalent constructs. We treat neuroepithelial stem-like cells with molecularly precise ligand nanopatterns displayed from solution using DNA origami. Notch signaling follows with clusters of Jag1, and with chimeric structures where most Jag1 proteins are replaced by other binders not targeting Notch. Our data rule out several confounding factors and suggest a model where Jag1 activates Notch upon prolonged binding without appearing to need a pulling force. These findings reveal a distinct mode of activation of Notch and lay the foundation for the development of soluble agonists.Peer reviewe
Multimode interference couplers: Design and applications
Electrical Engineering, Mathematics and Computer Scienc
High Capacity Integrated Optical Receivers
Electrical Engineering, Mathematics and Computer Scienc
InP-based Photonic Integrated Circuits for Wavelength Routing and Switching
Electrical Engineering, Mathematics and Computer Scienc
Phased-array wavelength demultiplexers and their integration with photodetectors
Electrical Engineering, Mathematics and Computer Scienc
Compact integrated optical components for telecommunication networks
Electrical Engineering, Mathematics and Computer Scienc
Red Soils from Various Parent Materials in Indonesia: The Prospect and Their Management Strategic
Distribution of red soils is about 50 million hectares, and generally potential for agricultural development in Indonesia. The soil was formed from various parent materials, such as andesitic-basaltic rock, acid tuff, limestone, ultra mafic rock, clay stone and sand stone. Generally the red soils were very developed soils, so that the sand mineralogy was dominated by minerals thatresistent to weathering such as quartz and opaque. The clay mineral was dominated by variable charge minerals which depends on pH like kaolinite followed by gibbsite, goethite, and hematite. These soils have very acid to slightly alkaline reaction, low exchangeable bases, low to high cation exchange capacity, and positive correlation to organic-C in the soil. The red soils according to Soil Taxonomy system could be classified as Inceptisols, Alfisols, Ultisols, and Oxisols. Characterization of the red soils areneeded before they are utilized for agriculture
DIFFERENTIATION IN PROPERTIES OF VERTISOL FROM VARIOUS PARENT MATERIALS
Vertisols is black and fertile soils, derived from various parent materials, dominated by smectite clay minerals, and charasterize by crack formation during dry season. Six soil profiles consisted of thirty two soil samples from dIfferent location were analyzed for their chemical and mineralogical composition at the laboratories of Soil Research Center for soil characteristics. Results indicate that the color matrix of Vertisols varies, hue range from 2.5Y to 10YR, color value varies from 2 to 6, and chroma range from 0 to 4. Clay mineral composition of Vertisols is dominated by smectite. Other clay minerals founded in the Vertisols are kaolinite, illite and vermiculite. The mineralogy composition of sand fraction is varies, some of them rich in weatherable minerals like andesine, amfibole, orthoclase, sanidin and the others are dominated by resistant minerals such as quartz and opaque. The mineralogical composition of Vertisols dependent on their parent material. The dominant cations in Vertisols are Ca
++ and Mg ++ . Vertisols from volcanic materials is dominated by Ca++ and followed by Mg cations, Vertisols from limestone is dominated by Ca++ , while Vertisols from peridotite is dominated by Mg ++ . All of the Vertisols studied have a high cation exchange capacity with pH’s range from 5.5 to 7.4. In using Vertisols for food plantation, should be consider the high content of Ca++
, Mg++ and the water management. The soils should be atleast always in moist condition, otherwise soils become very hard and cracks when dry
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