266 research outputs found

    Tangential Flow Filtration for Highly Efficient Concentration of Extracellular Vesicles from Large Volumes of Fluid

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    Concentration of extracellular vesicles (EVs) from biological fluids in a scalable and reproducible manner represents a major challenge. This study reports the use of tangential flow filtration (TFF) for the highly efficient isolation of EVs from large volumes of samples. When compared to ultracentrifugation (UC), which is the most widely used method to concentrate EVs, TFF is a more efficient, scalable, and gentler method. Comparative assessment of TFF and UC of conditioned cell culture media revealed that the former concentrates EVs of comparable physicochemical characteristics, but with higher yield, less single macromolecules and aggregates (<15 nm in size), and improved batch-to-batch consistency in half the processing time (1 h). The TFF protocol was then successfully implemented on fluids derived from patient lipoaspirate. EVs from adipose tissue are of high clinical relevance, as they are expected to mirror the regenerative properties of the parent cells

    Precise Measurement of the Spin Parameter of the Stellar-Mass Black Hole M33 X-7

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    In prior work, {\it Chandra} and Gemini-North observations of the eclipsing X-ray binary M33 X-7 have yielded measurements of the mass of its black hole primary and the system's orbital inclination angle of unprecedented accuracy. Likewise, the distance to the binary is known to a few percent. In an analysis based on these precise results, fifteen {\it Chandra} and {\it XMM-Newton} X-ray spectra, and our fully relativistic accretion disk model, we find that the dimensionless spin parameter of the black hole primary is a∗=0.77±0.05a_* = 0.77 \pm 0.05. The quoted 1-σ\sigma error includes all sources of observational uncertainty. Four {\it Chandra} spectra of the highest quality, which were obtained over a span of several years, all lead to the same estimate of spin to within statistical errors (2%), and this estimate is confirmed by 11 spectra of lower quality. There are two remaining uncertainties: (1) the validity of the relativistic model used to analyze the observations, which is being addressed in ongoing theoretical work; and (2) our assumption that the black hole spin is approximately aligned with the angular momentum vector of the binary, which can be addressed by a future X-ray polarimetry mission.Comment: 14 pages, 3 figures, 1 table, published in ApJ Letters; as explained in the erratum at the end of the text, the spin parameter has been corrected upward from a*=0.77 to a*=0.84. Apart from the addition of the erratum, the paper is unchanged

    Modelling the HI halo of the Milky Way

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    Aims: we studied the global distribution and kinematics of the extra-planar neutral gas in the Milky Way. Methods: we built 3D models for a series of Galactic HI layers, projected them for an inside view, and compared them with the Leiden-Argentina-Bonn 21-cm observations. Results: we show that the Milky Way disk is surrounded by an extended halo of neutral gas with a vertical scale-height of 1.6[+0.6/-0.4] kpc and an HI mass of 3.2[+1.0/-0.9]x10^8 solar masses, which is 5-10% of the total Galactic HI. This HI halo rotates more slowly than the disk with a vertical velocity gradient of -15[+/-4] km/s/kpc. We found evidence for a global infall motion, both vertical (20[+5/-7] km/s) and radial (30[+7/-5]km/s). Conclusions: the Milky Way HI halo shows properties similar to the halos of external galaxies and is compatible with being predominantly produced by supernova explosions in the disk. It is most likely composed of distinct gas complexes with masses of 10^4-10^5 solar masses of which the Intermediate Velocity Clouds are the local manifestations. The classical High Velocity Clouds appear to be a separate population.Comment: 13 pages, 9 figures, accepted for publication in A&

    The Grizzly, October 27, 2011

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    New U Fair Welcomes 40+ Vendors • String Ensemble to Make Debut Tomorrow • IT Department Hosts Tech Expo • Internship Profile: Rebecca Kamm • UCARE Community Week • Saturday Night Fun with the Nerf Club • PostSecret Comes to Ursinus College • Opinions: Graduation Change Irritates Students; Campus Safety is a Necessity, Not a Luxury • Roller Hockey Team Resurrected at Ursinus • Stortz and Narang Lead Bears into Cross Country Championships • Senior Spotlight: Jess Porcelan, Women\u27s Soccerhttps://digitalcommons.ursinus.edu/grizzlynews/1844/thumbnail.jp

    The Mock LISA Data Challenges: from Challenge 3 to Challenge 4

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    The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in Apr 2008, which demonstrated the positive recovery of signals from chirping Galactic binaries, from spinning supermassive--black-hole binaries (with optimal SNRs between ~ 10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Omega_gw(f) ~ 10^-11, slightly below the LISA instrument noise.Comment: 12 pages, 2 figures, proceedings of the 8th Edoardo Amaldi Conference on Gravitational Waves, New York, June 21-26, 200

    Optical Propagation and Communication

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    Contains an introduction and reports on five research projects.Maryland Procurement Office Contract MDA 904-90-C-5070National Science Foundation Grant ECS 87-18970National Institute of Standards and Technology Grant 60-NANBOD-1052U.S. Army Research Office Grant DAAL03-90-G-0128U.S. Army Research Office Contract DAAL03-87-K-0117U.S. Navy - Office of Naval Research Grant N00014-89-J-1163U.S. Air Force - Office of Scientific Research Contract F49620-87-C-0043U.S. Air Force - Office of Scientific Research Contract F49620-90-C-003

    Optical Propagation and Communication

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    Contains an introduction and reports on four research projects.Maryland Procurement Office Contract MDA 904-87-C-4044National Science Foundation Grant ECS 87-18970U.S. Army Research Office - Durham Contract DAAL03-87-K-0117U.S. Navy - Office of Naval Research Grant N00014-89-J-1163U.S. Air Force - Office of Scientific Research Contract F49620-87-C-004

    Optical Propagation and Communication

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    Contains an introduction and reports on five research projects.Maryland Procurement Office Contract MDA 904-90-C-5070National Science Foundation Grant ECS 87-18970National Institute of Standards and Technology Grant 60-NANBOD-1052U.S. Army Research Office Grant DAAL03-90-G-0128U.S. Army Research Office Contract DAAL03-87-K-0117U.S. Navy - Office of Naval Research Grant N00014-89-J-1163U.S. Air Force - Office of Scientific Research Contract F49620-90-C-003

    Building a Field: The Future of Astronomy with Gravitational Waves

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    Harnessing the sheer discovery potential of GW Astronomy will require bold, deliberate,and sustained efforts to train and develop the requisite workforce. The next decaderequires a strategic plan to build - from the ground up - a robust, open, andwell-connected GW Astronomy community with deep participation from traditionalastronomers, physicists, data scientists, and instrumentalists. This basic infrastructure issorely needed as an enabling foundation for research. We outline a set ofrecommendations for funding agencies, universities, and professional societies to helpbuild a thriving, diverse, and inclusive new field
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