ISGRI: the INTEGRAL Soft Gamma-Ray Imager

For the first time in the history of high energy astronomy, a large CdTe gamma-ray camera is operating in space. ISGRI is the low-energy camera of the IBIS telescope on board the INTEGRAL satellite. This paper details its design and its in-flight behavior and performances. Having a sensitive area of 2621 cm$^2$ with a spatial resolution of 4.6 mm, a low threshold around 12 keV and an energy resolution of $\sim$ 8% at 60 keV, ISGRI shows absolutely no signs of degradation after 9 months in orbit. All aspects of its in-flight behavior and scientific performance are fully nominal, and in particular the observed background level confirms the expected sensitivity of 1 milliCrab for a 10$^6$s observation.Comment: INTEGRAL A&A special issu

SPEAKER DIARIZATION IN THE ELISA CONSORTIUM OVER THE LAST 4 YEARS

International audienceThis paper summarizes the collaboration of the LIA and CLIPS laboratories, members of the ELISA consortium, along the last 4 year NIST speaker diarization system evaluation campaigns. In this context, two individual approaches, quite different, have been developed individually by each lab, to respond to the specific task of speaker segmentation. The first one relies on a classical two-step speaker segmentation strategy, based on the detection of speaker turns followed by a clustering process, while the second one corresponds to an integrated strategy where both segment boundaries and speaker tying of the segments are extracted simultaneously and challenged during the whole process. From these two main methods, various strategies were investigated for the fusion of segmentation results. Through the performance achieved along the different evaluation campaigns as well as the experience gained by the LIA and CLIPS labs in the speaker diarization task, a discussion about the overall work done in this evaluation context is drawn in this paper, proposing further investigation and progression

Voice biometrics over the internet in the framework of cost action 275

Original article can be found at: http://www.hindawi.com/journals/asp/ *Copyright Hindawi Publishing CorporationThe emerging field of biometric authentication over the Internet requires both robust person authentication and secure computer network protocols. This paper presents investigations of vocal biometric person authentication over the Internet, both at the protocol and authentication robustness levels. As part of this study, an appropriate client-server architecture for biometrics on the Internet is proposed and implemented. It is shown that the transmission of raw biometric data in this application is likely to result in unacceptably long delays in the process. On the other hand, by using data models (or features), the transmission time can be reduced to an acceptable level. The use of encryption/decryption for enhancing the data security in the proposed client-server link and its effects on the transmission time are also examined. Furthermore, the scope of the investigations includes an analysis of the effects of packet loss and speech coding on speaker verification performance. It is experimentally demonstrated that whilst the adverse effects of packet loss can be negligible, the encoding of speech, particularly at a low bit rate, can reduce the verification accuracy considerably. The paper details the experimental investigations conducted and presents an analysis of the results.Peer reviewe

Novel, Soluble Isoform of the Herpes Simplex Virus (HSV) Receptor Nectin1 (or PRR1-HIgR-HveC) Modulates Positively and Negatively Susceptibility to HSV Infection

A novel member of the nectin family, nectin1γ, was molecularly cloned. The cDNA has the same ectodomain as nectin1α and nectin1β, the two known transmembrane isoforms that serve as receptors for herpes simplex virus (HSV) entry into human cell lines (nectin1α and nectin1β, also called PRR1-HveC and HIgR, respectively). The 1.4-kb transcript, which originated by alternative splicing, is expressed in human cell lines, and appears to have a narrow distribution in human tissues. The sequence does not have a hydrophobic anchoring region, and the protein is secreted in the culture medium of cells transfected with the cDNA. Nectin1γ, purified from culture medium, can compete with membrane-bound nectin1β and reduce HSV infectivity. The expression of nectin1γ cDNA in cells resistant to HSV infection and lacking HSV receptors enables HSV to enter the cell, which implies that it is present at the cell surface. Thus, nectin1γ has the potential both to mediate and to reduce HSV entry into cells

Towards large scale multimedia indexing: a case study on person discovery in broadcast news

Comunicació presentada a: the 15th International Workshop on Content-Based Multimedia Indexing (CBMI'17), celebrat a Florència, Itàlia, del 19 al 21 de juny de 2017The rapid growth of multimedia databases and the human interest in their peers make indices representing the location and identity of people in audio-visual documents essential for searching archives. Person discovery in the absence of prior identity knowledge requires accurate association of audio-visual cues and detected names. To this end, we present 3 different strategies to approach this problem: clustering-based naming, verification-based naming, and graph-based naming. Each of these strategies utilizes different recent advances in unsupervised face / speech representation, verification, and optimization. To have a better understanding of the approaches, this paper also provides a quantitative and qualitative comparative study of these approaches using the associated corpus of the Person Discovery challenge at MediaEval 2016. From the results of our experiments, we can observe the pros and cons of each approach, thus paving the way for future promising research directions.This work was supported by the EU project EUMSSI (FP7-611057), ANR project MetaDaTV (ANR-14-CE24-0024) project, Camomile project (PCIN-2013-067), and the projects TEC2013-43935-R, TEC2015-69266-P, TEC2016-75976-R, TEC2015-65345-P financed by the Spanish government and ERDF