693 research outputs found
Clustering based active learning for evolving data streams
Data labeling is an expensive and time-consuming task. Choosing which labels to use is increasingly becoming important. In the active learning setting, a classifier is trained by asking for labels for only a small fraction of all instances. While many works exist that deal with this issue in non-streaming scenarios, few works exist in the data stream setting. In this paper we propose a new active learning approach for evolving data streams based on a pre-clustering step, for selecting the most informative instances for labeling. We consider a batch incremental setting: when a new batch arrives, first we cluster the examples, and then, we select the best instances to train the learner. The clustering approach allows to cover the whole data space avoiding to oversample examples from only few areas. We compare our method w.r.t. state of the art active learning strategies over real datasets. The results highlight the improvement in performance of our proposal. Experiments on parameter sensitivity are also reported
Expansion of activated cxcr5+icos+ tfh cells and plasmablasts induced by seasonal influenza vaccine is impaired in anti-il-6r treated rheumatoid arthritis patients
Objectives: To investigate the importance of IL-6 for the in vivo differentiation of human Tfh cells, taking advantage of influenza vaccination in patients under anti-IL-6R therapy.info:eu-repo/semantics/publishedVersio
CMB polarimetry with BICEP: instrument characterization, calibration, and performance
BICEP is a ground-based millimeter-wave bolometric array designed to target
the primordial gravity wave signature on the polarization of the cosmic
microwave background (CMB) at degree angular scales. Currently in its third
year of operation at the South Pole, BICEP is measuring the CMB polarization
with unprecedented sensitivity at 100 and 150 GHz in the cleanest available 2%
of the sky, as well as deriving independent constraints on the diffuse
polarized foregrounds with select observations on and off the Galactic plane.
Instrument calibrations are discussed in the context of rigorous control of
systematic errors, and the performance during the first two years of the
experiment is reviewed.Comment: 12 pages, 15 figures, updated version of a paper accepted for
Millimeter and Submillimeter Detectors and Instrumentation for Astronomy IV,
Proceedings of SPIE, 7020, 200
Transplantation tolerance: lessons from experimental rodent models
Immunological tolerance or functional unresponsiveness to a transplant is arguably the only approach that is likely to provide long-term graft survival without the problems associated with life-long global immunosuppression. Over the past 50 years, rodent models have become an invaluable tool for elucidating the mechanisms of tolerance to alloantigens. Importantly, rodent models can be adapted to ensure that they reflect more accurately the immune status of human transplant recipients. More recently, the development of genetically modified mice has enabled specific insights into the cellular and molecular mechanisms that play a key role in both the induction and maintenance of tolerance to be obtained and more complex questions to be addressed. This review highlights strategies designed to induce alloantigen specific immunological unresponsiveness leading to transplantation tolerance that have been developed through the use of experimental models
Absolute polarization angle calibration using polarized diffuse Galactic emission observed by BICEP
We present a method of cross-calibrating the polarization angle of a
polarimeter using BICEP Galactic observations. \bicep\ was a ground based
experiment using an array of 49 pairs of polarization sensitive bolometers
observing from the geographic South Pole at 100 and 150 GHz. The BICEP
polarimeter is calibrated to +/-0.01 in cross-polarization and less than +/-0.7
degrees in absolute polarization orientation. BICEP observed the temperature
and polarization of the Galactic plane (R.A= 100 degrees ~ 270 degrees and Dec.
= -67 degrees ~ -48 degrees). We show that the statistical error in the 100 GHz
BICEP Galaxy map can constrain the polarization angle offset of WMAP Wband to
0.6 degrees +\- 1.4 degrees. The expected 1 sigma errors on the polarization
angle cross-calibration for Planck or EPIC are 1.3 degrees and 0.3 degrees at
100 and 150 GHz, respectively. We also discuss the expected improvement of the
BICEP Galactic field observations with forthcoming BICEP2 and Keck
observations.Comment: 13 pages, 10 figures and 2 tables. To appear in Proceedings of SPIE
Astronomical Telescopes and Instrumentation 201
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