29 research outputs found
The source content of low galactic latitude XMM-Newton surveys
We present results from a project conducted by the Survey Science Center of
the XMM-Newton satellite and aiming at the identification and characterisation
of serendipitous EPIC sources at low galactic latitudes. Deep multi-colour
optical imaging and spectroscopic observations have been obtained in the
framework of several observing campaigns carried out at ING, CFHT and ESO.
These observations have lead to a number of optical identifications, mostly
with active stars. We describe the identified source content at low galactic
latitudes and compare stellar populations properties at low and high galactic
latitudes with those expected from stellar X-ray count models.Comment: Proceedings of the "X-ray surveys, in the light of the new
observatories" workshop, Astronomische Nachrichten, in the press (4 pages, 3
figures, uses an.cls
Diagnosis of focal liver lesions from ultrasound using deep learning
PURPOSE: The purpose of this study was to create an algorithm that simultaneously detects and characterizes (benign vs. malignant) focal liver lesion (FLL) using deep learning.
MATERIALS AND METHODS: We trained our algorithm on a dataset proposed during a data challenge organized at the 2018 Journées Francophones de Radiologie. The dataset was composed of 367 two-dimensional ultrasound images from 367 individual livers, captured at various institutions. The algorithm was guided using an attention mechanism with annotations made by a radiologist. The algorithm was then tested on a new data set from 177 patients.
RESULTS: The models reached mean ROC-AUC scores of 0.935 for FLL detection and 0.916 for FLL characterization over three shuffled three-fold cross-validations performed with the training data. On the new dataset of 177 patients, our models reached a weighted mean ROC-AUC scores of 0.891 for seven different tasks.
CONCLUSION: This study that uses a supervised-attention mechanism focused on FLL detection and characterization from liver ultrasound images. This method could prove to be highly relevant for medical imaging once validated on a larger independent cohort
Planck 2013 results. VI. High Frequency Instrument data processing
We describe the processing of the 531 billion raw data samples from the High Frequency Instrument (HFI), which we performed to produce six temperature maps from the first 473 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545, and 857GHz with an angular resolution ranging from 9.Ì7 to 4.Ì6. The detector noise per (effective) beam solid angle is respectively, 10, 6 , 12, and 39âÎŒK in the four lowest HFI frequency channels (100â353GHz) and 13 and 14âkJy sr-1 in the 545 and 857âGHz channels. Relative to the 143âGHz channel, these two high frequency channels are calibrated to within 5% and the 353âGHz channel to the percent level. The 100 and 217âGHz channels, which together with the 143âGHz channel determine the high-multipole part of the CMB power spectrum (50 <â < 2500), are calibrated relative to 143âGHz to better than 0.2%
Planck 2013 results. VI. High Frequency Instrument data processing
We describe the processing of the 531 billion raw data samples from the High Frequency Instrument (hereafter HFI), which we performed to produce six temperature maps from the first 473 days of Planck-HFI survey data. These maps provide an accurate rendition of the sky emission at 100, 143, 217, 353, 545, and 857 GHz with an angular resolution ranging from 9.7 to 4.6 arcmin. The detector noise per (effective) beam solid angle is respectively, 10, 6, 12 and 39 microKelvin in HFI four lowest frequency channel (100--353 GHz) and 13 and 14 kJy/sr for the 545 and 857 GHz channels. Using the 143 GHz channel as a reference, these two high frequency channels are intercalibrated within 5% and the 353 GHz relative calibration is at the percent level. The 100 and 217 GHz channels, which together with the 143 GHz channel determine the high-multipole part of the CMB power spectrum (50 < l <2500), are intercalibrated at better than 0.2 %
Affinities of nutty and green-smelling pyrazines and thiazoles to odorant-binding proteins, in relation with their lipophilicity
Thirty-two green- and/or nutty-smelling compounds, most of them pyrazine and thiazole derivatives, were tested in ligand binding assays with purified 19 kDa bovine and 22 kDa porcine olfactive binding proteins (OBPs). Unlike the nutty ones, all the green odorants were found to be good ligands for both proteins. Lipophilicity appears as an interesting discriminating physicochemical parameter, predictive of the affinity for OBPs and of the related odour profile