56 research outputs found
Solar Mikheyev-Smirnov-Wolfenstein Effect with Three Generations of Neutrinos
Under the assumption that the density variation of the electrons can be
approximated by an exponential function, the solar Mikheyev-Smirnov-Wolfenstein
effect is treated for three generations of neutrinos. The generalized
hypergeometric functions that result from the exact solution of this problem
are studied in detail, and a method for their numerical evaluation is
presented. This analysis plays a central role in the determination of neutrino
masses, not only the differences of their squares, under the assumption of
universal quark-lepton mixing.Comment: 22 pages, LaTeX, including 2 figure
Modulation instability induced by cross-phase modulation in a dual-wavelength dispersion-managed soliton fiber ring laser
We report on the observation of modulation instability induced by cross-phase
modulation in a dual-wavelength operation dispersion-managed soliton fiber ring
laser with net negative cavity dispersion. The passively mode-locked operation
is achieved by using nonlinear polarization rotation technique. A new type of
dual-wavelength operation, where one is femtosecond pulse and the other is
picosecond pulse operation, is obtained by properly rotating the polarization
controllers. When the dual-wavelength pulses are simultaneously circulating in
the laser ring cavity, a series of stable modulation sidebands appears in the
picosecond pulse spectrum at longer wavelength with lower peak power due to
modulation instability induced by cross-phase modulation between the two lasing
wavelengths. Moreover, the intensities and wavelength shifts of the modulation
sidebands can be tuned by varying the power of the femtosecond pulse or the
lasing central wavelengths of the dual-wavelength pulses. The theoretical
analysis of the modulation instability induced by cross-phase modulation in our
fiber laser is also presented.Comment: 26 pages, 10 figure
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Chemokine receptor CCR3 is important for migration of mast cells in neurofibroma
Background Neurofibroma consists of abundant extracellular matrix and many types of cells, including Schwann cells (SCs), mast cells (MCs), fibroblasts and endothelial cells. As SCs have been found to be the cell of origin for neurofibroma, how MCs may migrate into the tumor has not been fully clarified. Given that chemokine receptor CCR3 is found predominantly expressed by differentiated MCs, we postulated that CCR3 may play a role in the homing of MCs to neurofibroma. The goal of this study is to investigate the possible involvement of chemokine receptor CCR3 in the migration of MCs to the neurofibroma. Methods Expressional and functional assays for CCR3 and its ligands were performed on MCs and SCs. Results By real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, we found one of the CCR3 ligand, CCL7 was highly expressed by murine SC cell line SW10, and also moderately expressed by MCs. In serial chemotaxis assays, MCs were found specifically responsive to CCL7 and also condition medium from SW10 cells, indicating SCs may attract MCs by CCR3-mediated cell migration. Conclusion The interaction of CCR3 and CCL7 may play important roles for MC migration toward SC in the neurofibroma. Copyright (C) 2010, Taiwanese Dermatological Association. Published by Elsevier Taiwan LLC. All rights reserved
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