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Landmark detection in 2D bioimages for geometric morphometrics: a multi-resolution tree-based approach
The detection of anatomical landmarks in bioimages is a necessary but tedious step for geometric morphometrics studies in many research domains. We propose variants of a multi-resolution tree-based approach to speed-up the detection of landmarks in bioimages. We extensively evaluate our method variants on three different datasets (cephalometric, zebrafish, and drosophila images). We identify the key method parameters (notably the multi-resolution) and report results with respect to human ground truths and existing methods. Our method achieves recognition performances competitive with current existing approaches while being generic and fast. The algorithms are integrated in the open-source Cytomine software and we provide parameter configuration guidelines so that they can be easily exploited by end-users. Finally, datasets are readily available through a Cytomine server to foster future research
A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
The observation of a gamma-ray line in the cosmic-ray fluxes would be a
smoking-gun signature for dark matter annihilation or decay in the Universe. We
present an improved search for such signatures in the data of the Fermi Large
Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides
updating to 43 months of data, we use a new data-driven technique to select
optimized target regions depending on the profile of the Galactic dark matter
halo. In regions close to the Galactic center, we find a 4.6 sigma indication
for a gamma-ray line at 130 GeV. When taking into account the look-elsewhere
effect the significance of the observed excess is 3.2 sigma. If interpreted in
terms of dark matter particles annihilating into a photon pair, the
observations imply a dark matter mass of 129.8\pm2.4^{+7}_{-13} GeV and a
partial annihilation cross-section of = 1.27\pm0.32^{+0.18}_{-0.28}
x 10^-27 cm^3 s^-1 when using the Einasto dark matter profile. The evidence for
the signal is based on about 50 photons; it will take a few years of additional
data to clarify its existence.Comment: 23 pages, 9 figures, 3 tables; extended discussion; matches published
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