76,646 research outputs found
Development of an infinite input impedance fluidic amplifier
Two-phase analog infinite input impedance high stable gain fluid amplifie
Critical view of the claimed pentaquark
We use a theoretical model of the reaction
adapted to the experiment done at LEPS where a peak was observed and associated
to the pentaquark. The study shows that the method used in
the experiment to associate momenta to the undetected proton and neutron,
together with the chosen cuts, necessarily creates an artificial broad peak in
the assumed invariant mass in the region of the claimed
. It is shown that the LEPS fit to the data, used to make the
claim of the , grossly distorts the background. An
alternative fit, assuming a background plus a fluctuation, returns a background
practically equal to the theoretical one and a fluctuation identical to the one
seen in the experimental spectrum of 2 significance.Comment: Conference Proceedin
An analytic Pade-motivated QCD coupling
We consider a modification of the Minimal Analytic (MA) coupling of Shirkov
and Solovtsov. This modified MA (mMA) coupling reflects the desired analytic
properties of the space-like observables. We show that an approximation by
Dirac deltas of its discontinuity function is equivalent to a Pad\'e
(rational) approximation of the mMA coupling that keeps its analytic structure.
We propose a modification to mMA that, as preliminary results indicate, could
be an improvement in the evaluation of low-energy observables compared with
other analytic couplings.Comment: 2 pages, 1 figure (double), to appear in the Proceedings of the VIII
Latin American Symposium on Nuclear Physics and Applications, Santiago,
Chile, 15-19 December 2009. Poster presented by H. E. Martine
The Presence of GC-C in Extracellular Vesicles Secreted by Colorectal Cancer Cells
Background: Guanylyl Cyclase C (GC-C) is a membrane-bound protein found on intestinal epithelial cells involved in the activation of CFTR. This protein has previously been involved in the development of colorectal cancer.
Extracellular vesicles (EVs) are bilayered vesicles of varying size (30 to 1,000 + nm in diameter) that believed to be secreted by all cells in the human body. In the past decade, EVs have garnered attention due to their impact in the field of oncology, where they have been shown to potentially serve as biomarkers for various cancers.
In this study, we looked at the EVs secreted by GC-C+ and GC-C- cell lines. We expected GC-C to be present on the EVs secreted by GC-C+ cell lines and that this finding may intake a role for GC-C at tissues distal to the intestinal epithelial cells.
Methods: GC-C+ cells lines (T84 and CT26-hGCC) and GC-C- cell lines (SW480 and CT26-WT) were cultured and their media was harvested, then ultracentrifuged to extract the EVs from the media. These EVs were then checked for the presence and absence of various markers (GC-C, Calnexin, TSG101) via Western Blot. Exosome size was assessed via NTA to further provide evidence for the identity of these EVs.
Results: Western blot confirmed the presence of TSG101 in both EV types samples, as well as the presence of GC-C in EVs derived from GC-C+ cell lines, but not from GC-C- cell lines. Calnexin was found to be absent in EV samples, excluding the possibility of lysate contamination. NTA analysis confirmed the correct size for the exosomes in sample.
Discussion: This study assessed the contents of EVs secreted by colorectal cancer cell lines. Our findings indicate the presence of GC-C on exosomes and microvesicles. Further studies will need to be conducted in order to assess the function of these GC-C+ EVs in the setting of colorectal cancer
Fermionic entanglement ambiguity in non-inertial frames
We analyse an ambiguity in previous works on entanglement of fermionic fields
in non-inertial frames. This ambiguity, related to the anticommutation
properties of field operators, leads to non-unique results when computing
entanglement measures for the same state. We show that the ambiguity disappears
when we introduce detectors, which are in any case necessary as a means to
probe the field entanglement.Comment: 9 pages, 4 figures. Revtex 4.1, added Journal referenc
Redistribution of particle and anti-particle entanglement in non-inertial frames
We analyse the entanglement tradeoff between particle and anti-particle modes
of a Dirac field from the perspective of inertial and uniformly accelerated
observers. Our results show that a redistribution of entanglement between
particle and anti-particle modes plays a key role in the survival of fermionic
field entanglement in the infinite acceleration limit.Comment: 10 pages, 5 figures, revtex4. Added journal referenc
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