Multimodal Signal Processing and Learning Aspects of Human-Robot Interaction for an Assistive Bathing Robot

We explore new aspects of assistive living on smart human-robot interaction (HRI) that involve automatic recognition and online validation of speech and gestures in a natural interface, providing social features for HRI. We introduce a whole framework and resources of a real-life scenario for elderly subjects supported by an assistive bathing robot, addressing health and hygiene care issues. We contribute a new dataset and a suite of tools used for data acquisition and a state-of-the-art pipeline for multimodal learning within the framework of the I-Support bathing robot, with emphasis on audio and RGB-D visual streams. We consider privacy issues by evaluating the depth visual stream along with the RGB, using Kinect sensors. The audio-gestural recognition task on this new dataset yields up to 84.5%, while the online validation of the I-Support system on elderly users accomplishes up to 84% when the two modalities are fused together. The results are promising enough to support further research in the area of multimodal recognition for assistive social HRI, considering the difficulties of the specific task. Upon acceptance of the paper part of the data will be publicly available

Audio-assisted movie dialogue detection

An audio-assisted system is investigated that detects if a movie scene is a dialogue or not. The system is based on actor indicator functions. That is, functions which define if an actor speaks at a certain time instant. In particular, the crosscorrelation and the magnitude of the corresponding the crosspower spectral density of a pair of indicator functions are input to various classifiers, such as voted perceptrons, radial basis function networks, random trees, and support vector machines for dialogue/non-dialogue detection. To boost classifier efficiency AdaBoost is also exploited. The aforementioned classifiers are trained using ground truth indicator functions determined by human annotators for 41 dialogue and another 20 non-dialogue audio instances. For testing, actual indicator functions are derived by applying audio activity detection and actor clustering to audio recordings. 23 instances are randomly chosen among the aforementioned 41 dialogue instances, 17 of which correspond to dialogue scenes and 6 to non-dialogue ones. Accuracy ranging between 0.739 and 0.826 is reported

Audio-assisted movie dialogue detection

An audio-assisted system is investigated that detects if a movie scene is a dialogue or not. The system is based on actor indicator functions. That is, functions which define if an actor speaks at a certain time instant. In particular, the cross-correlation and the magnitude of the corresponding the cross-power spectral density of a pair of indicator functions are input to various classifiers, such as voted perceptions, radial basis function networks, random trees, and support vector machines for dialogue/non-dialogue detection. To boost classifier efficiency AdaBoost is also exploited. The aforementioned classifiers are trained using ground truth indicator functions determined by human annotators for 41 dialogue and another 20 non-dialogue audio instances. For testing, actual indicator functions are derived by applying audio activity detection and actor clustering to audio recordings. 23 instances are randomly chosen among the aforementioned 41 dialogue instances, 17 of which correspond to dialogue scenes and 6 to non-dialogue ones. Accuracy ranging between 0.739 and 0.826 is reported. © 2008 IEEE

Homogeneous immunoassay for cyclopiazonic acid based upon mimotopes and upconversion-resonance energy transfer

Strains of Penicillium spp. are used for fungi-ripened cheeses and Aspergillus spp. routinely contaminate maize and other crops. Some of these strains can produce toxic secondary metabolites (mycotoxins), including the neurotoxin α-cyclopiazonic acid (CPA). In this work, we developed a homogeneous upconversion-resonance energy transfer (UC-RET) immunoassay for the detection of CPA using a novel epitope mimicking peptide, or mimotope, selected by phage display. CPA-specific antibody was used to isolate mimotopes from a cyclic 7-mer peptide library in consecutive selection rounds. Enrichment of antibody binding phages was achieved, and the analysis of individual phage clones revealed four different mimotope peptide sequences. The mimotope sequence, ACNWWDLTLC, performed best in phage-based immunoassays, surface plasmon resonance binding analyses, and UC-RET-based immunoassays. To develop a homogeneous assay, upconversion nanoparticles (UCNP, type NaYF4:Yb3+, Er3+) were used as energy donors and coated with streptavidin to anchor the synthetic biotinylated mimotope. Alexa Fluor 555, used as an energy acceptor, was conjugated to the anti-CPA antibody fragment. The homogeneous single-step immunoassay could detect CPA in just 5 min and enabled a limit of detection (LOD) of 30 pg mL-1 (1.5 μg kg-1) and an IC50 value of 0.36 ng mL-1. No significant cross-reactivity was observed with other co-produced mycotoxins. Finally, we applied the novel method for the detection of CPA in spiked maize samples using high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) as a reference method.This work has been funded by the Ministry of Science, Innovation and Universities (MSIU) (RTI2018-096410-B-C21, PID2021-127457OB-C21 and PID2019-105237 GB-I00). FP acknowledges the MSIU for an FPU contract.S

Regionally Distinct N -Methyl-D-Aspartate Receptors Distinguished by Quantitative Autoradiography of [ 3 H]MK-801 Binding in Rat Brain

Quantitative autoradiography of [ 3 H]MK-801 binding was used to characterize regional differences in N -methyl-d-aspartate (NMDA) receptor pharmacology in rat CNS. Regionally distinct populations of NMDA receptors were distinguished on the basis of regulation of [ 3 H]MK-801 binding by the NMDA antagonist 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP). CPP inhibited [ 3 H]MK-801 binding in outer cortex (OC) and medial cortex (MC) with apparent K i values of 0.32-0.48 Μ M , whereas in the medial striatum (MS), lateral striatum (LS), CA1, and dentate gyrus (DG) of hippocampus, apparent K i values were 1.1-1.6 Μ M . In medial thalamus (MT) and lateral thalamus (LT) the apparent K i values were 0.78 Μ M . In the presence of added glutamate (3 Μ M ), the relative differences in apparent K i values between regions maintained a similar relationship with the exception of the OC. Inhibition of [ 3 H]MK-801 binding by the glycine site antagonist 7-chlorokynurenic acid (7-ClKyn) distinguished at least two populations of NMDA receptors that differed from populations defined by CPP displacement. 7-ClKyn inhibited [ 3 H]MK-801 binding in OC, MC, MS, and LS with apparent K i values of 6.3-8.6 Μ M , whereas in CA1, DG, LT, and MT, K i values were 11.4-13.6 Μ M . In the presence of added glycine (1 Μ M ), the relative differences in apparent K i values were maintained. Under conditions of differential receptor activation, regional differences in NMDA receptor pharmacology can be detected using [ 3 H]MK-801 binding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65616/1/j.1471-4159.1993.tb03295.x.pd

A study of cortical and hippocampal NMDA and PCP receptors following selective cortical and subcortical lesions

The neuronal localization of glutamate and phencyclidine (PCP) receptors was evaluated in the cerebral cortex and hippocampal formation of rat CNS using quantitative autoradiography. Scatchard analysis of [3H]glutamate binding in the cortex (layers I and II and V and VI) showed no difference in the total number of binding sites (Bmax) or apparent affinity (Kd) 1 week, 1 month and 2 months following unilateral ibotenate lesions to nucleus basalis of Meynert (nbM) compared to the non-lesioned side. Quisqualic acid displacement of [3H]glutamate in layers I and II, 1 week following nbM destruction, revealed both high- and low-affinity binding sites (representing the quisqualate (QA) and (NMDA) sites, respectively). Compared to the control side, there was no difference in binding parameters for either of the receptors sites. In similarly lesioned animals, the NMDA receptor was specifically labelled with [3H]glutamate and the associated PCP receptor labelled with [3H]N-(1-[2-thienyl]cyclohexyl)3,4-piperidine ([3H]TCP) in adjacent brain sections. For both receptors, there was no change in the total number of binding sites in the cortex following destruction of nbM. On the other hand, virtually all binding to NMDA and PCP receptors was eliminated following chemical destruction of intrinsic cortical neurons. These results suggest that the NMDA/PCP receptor complex does not exist on the terminals of cortical cholinergic afferents. One week after knife cuts of the glutamatergic entorhinal pathway to the hippocampal formation only an approximate 10% reduction of NMDA and PCP receptors was seen in the dentate gyrus. Conversely, selective destruction of the dentate granule cells using colchicine caused a near identical loss of NMDA and PCP receptors (84% vs 92% respectively). It is concluded from these experiments that glutamate and PCP receptors exist almost exclusively on neurons intrinsic to the hippocampal formation and that no more than 10% of NMDA and PCP receptors exist as autoreceptors on glutamatergic terminals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29507/1/0000594.pd

Loss of hippocampal [3H]TCP binding in Alzheimer's disease

We have previously demonstrated a marked loss in (NMDA) receptors in the hippocampus and cerebral cortex of patients dying with dementia of the Alzheimer type (DAT). In addition, we have found that the dissociative anesthetic N-(1-[2-thienyl]cyclohexyl)3,4-piperidine ([3H]TCP) binds to a site whose regional distribution is highly correlated with that of NMDA receptor sites. We studied the binding of [3H]TCP to sections of hippocampi from 8 controls, 12 patients with DAT and 7 patients with other dementias. [3H]TCP binding was significantly reduced in strata pyramidalia of CA1/CA2, CA3 and subiculum of DAT hippocampal formation compared to that of control. Labelled dissociative anestheties could potentially be used with positron emission tomography in the diagnosis of DAT.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26773/1/0000325.pd