Robust indoor speaker recognition in a network of audio and video sensors

AbstractSituational awareness is achieved naturally by the human senses of sight and hearing in combination. Automatic scene understanding aims at replicating this human ability using microphones and cameras in cooperation. In this paper, audio and video signals are fused and integrated at different levels of semantic abstractions. We detect and track a speaker who is relatively unconstrained, i.e., free to move indoors within an area larger than the comparable reported work, which is usually limited to round table meetings. The system is relatively simple: consisting of just 4 microphone pairs and a single camera. Results show that the overall multimodal tracker is more reliable than single modality systems, tolerating large occlusions and cross-talk. System evaluation is performed on both single and multi-modality tracking. The performance improvement given by the audio–video integration and fusion is quantified in terms of tracking precision and accuracy as well as speaker diarisation error rate and precision–recall (recognition). Improvements vs. the closest works are evaluated: 56% sound source localisation computational cost over an audio only system, 8% speaker diarisation error rate over an audio only speaker recognition unit and 36% on the precision–recall metric over an audio–video dominant speaker recognition method

A Peptidic Thymidylate-Synthase Inhibitor Loaded on Pegylated Liposomes Enhances the Antitumour Effect of Chemotherapy Drugs in Human Ovarian Cancer Cells

There is currently no effective long-term treatment for ovarian cancer (OC) resistant to poly-chemotherapy regimens based on platinum drugs. Preclinical and clinical studies have demonstrated a strong association between development of Pt-drug resistance and increased thymidylate synthase (hTS) expression, and the consequent cross-resistance to the hTS inhibitors 5-fluorouracil (5-FU) and raltitrexed (RTX). In the present work, we propose a new tool to combat drug resistance. We propose to treat OC cell lines, both Pt-sensitive and -resistant, with dual combinations of one of the four chemotherapeutic agents that are widely used in the clinic, and the new peptide, hTS inhibitor, [D-Gln4]LR. This binds hTS allosterically and, unlike classical inhibitors that bind at the catalytic pocket, causes cell growth inhibition without inducing hTS overexpression. The dual drug combinations showed schedule-dependent synergistic antiproliferative and apoptotic effects. We observed that the simultaneous treatment or 24h pre-treatment of OC cells with the peptide followed by either agent produced synergistic effects even in resistant cells. Similar synergistic or antagonistic effects were obtained by delivering the peptide into OC cells either by means of a commercial delivery system (SAINT-PhD) or by pH sensitive PEGylated liposomes. Relative to non-PEGylated liposomes, the latter had been previously characterized and found to allow macrophage escape, thus increasing their chance to reach the tumour tissue. The transition from the SAINT-PhD delivery system to the engineered liposomes represents an advancement towards a more drug-like delivery system and a further step towards the use of peptides for in vivo studies. Overall, the results suggest that the association of standard drugs, such as cDDP and/or 5-FU and/or RTX, with the novel peptidic TS inhibitor encapsulated into PEGylated pH-sensitive liposomes can represent a promising strategy for fighting resistance to cDDP and anti-hTS drugs

Speaker tracking in a joint audio-video network

Situational awareness is achieved naturally by the human senses of sight and hearing in combination. System-level automatic scene understanding aims at replicating this human ability using cooperative microphones and cameras. In this thesis, we integrate and fuse audio and video signals at different levels of abstractions to detect and track a speaker in a scenario where people are free to move indoors. Despite the low complexity of the system, which consists of just 4 microphones pairs and 1 camera, results show that the overall multimodal tracker is more reliable than single modality systems, tolerating large occlusions and cross-talking. The system evaluation is performed on both single modality and multimodality tracking. The performance improvement given by the audio-video integration and fusion is quantified in terms of tracking precision and accuracy as well as speaker diarisation error rate and precision-recall recognition metrics. We evaluate our results vs. the closest works: a 56% improvement on audio only sound source localisation computational cost and an 18% increment on the speaker diarisation error rate over a speaker-only unit is achieved.EPSR

Conveying a newly designed hydrophilic anti-human thymidylate synthase peptide to cisplatin resistant cancer cells: are pH-sensitive liposomes more effective than conventional ones?

Context: LR-peptide, a novel hydrophilic peptide synthetized and characterized in previous work, is able to reduce the multi-drug resistance response in cisplatin (cDPP) resistant cancer cells by inhibiting human thymidylate synthase overexpressed in several tumors, including ovarian and colon-rectal cancers, but it is unable to enter the cells spontaneously. Objective: The aim of this work was to design and characterize liposomal vesicles as drug delivery systems for the LR peptide, evaluating the possible benefits of the pH-responsive feature in improving intracellular delivery. Materials and methods For this purpose, conventional and pH-sensitive liposomes were formulated, compared regarding their physical-chemical properties (size, PDI, morphology, in vitro stability and drug release) and studied for in vitro cytotoxicity against a cDDP-resistant cancer cells. Results and discussion Results indicated that LR peptide was successfully encapsulated in both liposomal formulations but at short incubation time only LR loaded pH-sensitive liposomes showed cell inhibition activity while for long incubation time the two kinds of liposomes demonstrated the same efficacy. Conclusions Data provide evidence that acidic pH-triggered liposomal delivery is able to significantly reduce the time required by the systems to deliver the drug to the cells without inducing an enhancement of the efficacy of the drug

pH sensitive PEGylated Liposomes delivering active hydrophilic peptide with anticancer activity: in vitro study on cDDP-resistant ovarian cell line

Thymidylate synthase (TS) can be considered a very interesting molecular target for the therapy of the ovarian cancer.. Recently, specific octapeptides able to reduce the growth of platinum-resistant cells by inhibiting the enzyme human thymidylate synthase (hTS), have been identified. Similarly to the majority of peptides, they cannot cross the cell membrane and require a delivery system for transport into the cells and pH sensitive liposomes, destabilizing at mildly acidic pH, are considered efficient tools for delivering water-soluble drugs into the cell cytoplasm. In the present study in order to attain the peptide triggering in the cells promoting endosomal escape, stealth pH-sensitive liposomes were developed and characterized. Results suggested that pH sensitive liposomes seemed suitable carriers for the encapsulation of small hydrophilic molecules like peptides. The appreciable difference in cytotoxicity between loaded and unloaded liposomes demonstrated that the peptide, whose activity is held in the cytoplasm, was triggered in the proper biological site