268 research outputs found
Tangential Flow Filtration for Highly Efficient Concentration of Extracellular Vesicles from Large Volumes of Fluid
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
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 . The quoted 1- 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
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
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
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
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
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
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
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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