Correction: Kumar et al. Face Spoofing, Age, Gender and Facial Expression Recognition Using Advance Neural Network Architecture-Based Biometric System. Sensors 2022, 22, 5160.

In the original publication [...].

Contributions to Power Grid System Analysis Based on Clustering Techniques.

The topic addressed in this article is part of the current concerns of modernizing power systems by promoting and implementing the concept of smart grid(s). The concepts of smart metering, a smart home, and an electric car are developing simultaneously with the idea of a smart city by developing high-performance electrical equipment and systems, telecommunications technologies, and computing and infrastructure based on artificial intelligence algorithms. The article presents contributions regarding the modeling of consumer classification and load profiling in electrical power networks and the efficiency of clustering techniques in their profiling as well as the simulation of the load of medium-voltage/low-voltage network distribution transformers to electricity meters.

Face Spoofing, Age, Gender and Facial Expression Recognition Using Advance Neural Network Architecture-Based Biometric System.

Nowadays, the demand for soft-biometric-based devices is increasing rapidly because of the huge use of electronics items such as mobiles, laptops and electronic gadgets in daily life. Recently, the healthcare department also emerged with soft-biometric technology, i.e., face biometrics, because the entire data, i.e., (gender, age, face expression and spoofing) of patients, doctors and other staff in hospitals is managed and forwarded through digital systems to reduce paperwork. This concept makes the relation friendlier between the patient and doctors and makes access to medical reports and treatments easier, anywhere and at any moment of life. In this paper, we proposed a new soft-biometric-based methodology for a secure biometric system because medical information plays an essential role in our life. In the proposed model, 5-layer U-Net-based architecture is used for face detection and Alex-Net-based architecture is used for classification of facial information i.e., age, gender, facial expression and face spoofing, etc. The proposed model outperforms the other state of art methodologies. The proposed methodology is evaluated and verified on six benchmark datasets i.e., NUAA Photograph Imposter Database, CASIA, Adience, The Images of Groups Dataset (IOG), The Extended Cohn-Kanade Dataset CK+ and The Japanese Female Facial Expression (JAFFE) Dataset. The proposed model achieved an accuracy of 94.17% for spoofing, 83.26% for age, 95.31% for gender and 96.9% for facial expression. Overall, the modification made in the proposed model has given better results and it will go a long way in the future to support soft-biometric based applications.

GrAb: A Deep Learning-Based Data-Driven Analytics Scheme for Energy Theft Detection.

Integrating information and communication technology (ICT) and energy grid infrastructures introduces smart grids (SG) to simplify energy generation, transmission, and distribution. The ICT is embedded in selected parts of the grid network, which partially deploys SG and raises various issues such as energy losses, either technical or non-technical (i.e., energy theft). Therefore, energy theft detection plays a crucial role in reducing the energy generation burden on the SG and meeting the consumer demand for energy. Motivated by these facts, in this paper, we propose a deep learning (DL)-based energy theft detection scheme, referred to as GrAb, which uses a data-driven analytics approach. GrAb uses a DL-based long short-term memory (LSTM) model to predict the energy consumption using smart meter data. Then, a threshold calculator is used to calculate the energy consumption. Both the predicted energy consumption and the threshold value are passed to the support vector machine (SVM)-based classifier to categorize the energy losses into technical, non-technical (energy theft), and normal consumption. The proposed data-driven theft detection scheme identifies various forms of energy theft (e.g., smart meter data manipulation or clandestine connections). Experimental results show that the proposed scheme (GrAb) identifies energy theft more accurately compared to the state-of-the-art approaches.

Modulation of Beta oscillations in the subthalamic nucleus with prosaccades and antisaccades in Parkinson's disease.

Increased oscillations in the beta band are thought to be related to motor symptoms of Parkinson's disease (PD). Previous studies have shown that beta-band desynchronization in the subthalamic nucleus (STN) is reduced just before and during limb movements. While the STN is part of the basal ganglia (BG)-thalamocortical circuit controlling limb movements, it is also part of the BG-brainstem projection controlling saccadic eye movements. Late-stage PD patients have deficits in saccades in addition to difficulties with limb movements arising from impaired functions of the BG. We investigated saccade-related changes in beta-band (15-30 Hz) oscillatory activities in the human STN while PD patients performed visually guided prosaccades and antisaccades, the latter requiring suppression of reflexive responses and volitional initiation of saccades. We recorded local field potentials from deep brain stimulation electrodes implanted in the STN in human PD patients 1-5 d after surgery and compared prosaccades and antisaccades with these and with limb movements. Saccade-related beta-band desynchronizations were observed just before and during saccades in all subjects, suggesting that reduction of beta-band oscillatory activity in the STN is related to preparation and execution of saccades. Furthermore, beta-band desynchronizations for antisaccades started earlier, were sustained for longer periods, were of greater magnitude, and were observed more often than prosaccades. Beta-band desynchronization in the STN may reflect the additional processes associated with suppression of reflexive responses and volitional execution of saccades in the opposite direction.

Decoupling the actions of the eyes from the hand alters beta and gamma synchrony within SPL.

Eye-hand coordination is crucial for our ability to interact with the world around us. However, much of the visually guided reaches that we perform require a spatial decoupling between gaze direction and hand orientation. These complex decoupled reaching movements are in contrast to more standard eye and hand reaching movements in which the eyes and the hand are coupled. The superior parietal lobule (SPL) receives converging eye and hand signals; however, what is yet to be understood is how the activity within this region is modulated during decoupled eye and hand reaches. To address this, we recorded local field potentials within SPL from two rhesus macaques during coupled vs. decoupled eye and hand movements. Overall we observed a distinct separation in synchrony within the lower 10- to 20-Hz beta range from that in the higher 30- to 40-Hz gamma range. Specifically, within the early planning phase, beta synchrony dominated; however, the onset of this sustained beta oscillation occurred later during eye-hand decoupled vs. coupled reaches. As the task progressed, there was a switch to low-frequency and gamma-dominated responses, specifically for decoupled reaches. More importantly, we observed local field potential activity to be a stronger task (coupled vs. decoupled) and state (planning vs. execution) predictor than that of single units alone. Our results provide further insight into the computations of SPL for visuomotor transformations and highlight the necessity of accounting for the decoupled eye-hand nature of a motor task when interpreting movement control research data.

Stacked Model-Based Classification of Parkinson's Disease Patients Using Imaging Biomarker Data.

Parkinson's disease (PSD) is a neurological disorder of the brain where nigrostriatal integrity functions lead to motor and non-motor-based symptoms. Doctors can assess the patient based on the patient's history and symptoms; however, the symptoms are similar in various neurodegenerative diseases, such as progressive supranuclear palsy (PSP), multiple system atrophy-parkinsonian type (MSA), essential tremor, and Parkinson's tremor. Thus, sometimes it is difficult to identify a patient's disease based on his or her symptoms. To address the issue, we have used neuroimaging biomarkers to analyze dopamine deficiency in the brains of subjects. We generated the different patterns of dopamine levels inside the brain, which identified the severity of the disease and helped us to measure the disease progression of the patients. For the classification of the subjects, we used machine learning (ML) algorithms for a multivariate classification of the subjects using neuroimaging biomarkers data. In this paper, we propose a stacked machine learning (ML)-based classification model to identify the HC and PSD subjects. In this stacked model, meta learners can learn and combine the predictions from various ML algorithms, such as K-nearest neighbor (KNN), random forest algorithm (RFA), and Gaussian naive Bayes (GANB) to achieve a high performance model. The proposed model showed 92.5% accuracy, outperforming traditional schemes.

Cardiac Tissue-Mimicking Ballistic Gel Phantom for Ultrasound Imaging in Clinical and Research Applications.

Ballistic gel was investigated as a tissue-mimicking material in an anthropomorphic cardiac phantom for ultrasound imaging. The gel was tested for its acoustic properties and its compatibility with conventional plastics molding techniques. Speed of sound and attenuation were evaluated in the range 2-12 MHz. The speed of sound was 1537 ± 39 m/s, close to typical values for cardiac tissue (∼1576 m/s). The attenuation coefficient was 1.07 dB/cm·MHz, within the range of values previously reported for cardiac tissue (0.81-1.81 dB/cm·MHz). A cardiac model based on human anatomy was developed using established image segmentation processes and conventional plastic molding techniques. Key anatomic features were observed, captured and identified in the model using an intracardiac ultrasound imaging system. These favorable results along with the material's durability and processes that allow for repetitive production of detailed whole-heart models at low cost are promising. There are numerous applications for geometrically complex phantoms in research, training, device development and clinical use.

Stopping and slowing manual and spoken responses: Similar oscillatory signatures recorded from the subthalamic nucleus.

Response control in the forms of stopping and slowing responses is thought to be implemented by a frontal-subcortical network, which includes the subthalamic nucleus (STN). For manual control, stopping is linked to STN beta (13-30 Hz) and slowing responses are linked to lower frequencies (<12 Hz). Whether similar STN oscillatory activities are associated with the control of spoken responses is not clear. We studied 16 patients with STN LFP recordings during manual and vocal stop signal tasks in two experiments. We found increased beta activities for stopping spoken responses, similar to manual stopping. However, unlike manual stopping, stopping spoken responses elicited a right-lateralized beta power increase, which may be related to previously reported hyperactivity of right-sided motor control regions in stuttering. We additionally studied STN power changes associated with slowing responses in the same stop-signal tasks by comparing slower vs. faster go trials. Now, rather than beta, there was an alpha power increase after Go cues, which remained elevated only in slower Go trials in both the vocal and manual tasks. These data show that different types of response control are generalizable across effectors and relate to different frequencies recorded from the STN.

Time-course of coherence in the human basal ganglia during voluntary movements.

We are interested in characterizing how brain networks interact and communicate with each other during voluntary movements. We recorded electrical activities from the globus pallidus pars interna (GPi), subthalamic nucleus (STN) and the motor cortex during voluntary wrist movements. Seven patients with dystonia and six patients with Parkinson's disease underwent bilateral deep brain stimulation (DBS) electrode placement. Local field potentials from the DBS electrodes and scalp EEG from the electrodes placed over the motor cortices were recorded while the patients performed externally triggered and self-initiated movements. The coherence calculated between the motor cortex and STN or GPi was found to be coupled to its power in both the beta and the gamma bands. The association of coherence with power suggests that a coupling in neural activity between the basal ganglia and the motor cortex is required for the execution of voluntary movements. Finally, we propose a mathematical model involving coupled neural oscillators which provides a possible explanation for how inter-regional coupling takes place.

Use of bipolar parallel electrodes for well-controlled microstimulation in a mouse hippocampal brain slice.

In a hippocampal brain slice two types of stimulating electrodes [single (SE) or monopolar and parallel bipolar (PE)] were used to determine the optimal protocol for single pulse microstimulation. We show that even for a constant-current power source the amplitude of stimulating current (SC) is not constant, especially for short pulse widths (PW) (<200 micros). Recording the stimulating current and computing the amount of electric charge that is passed through the microelectrode gives the best estimate of the strength of electrical stimulation. For SE the evoked response is obstructed for a time interval larger than three times the PW. The stimulus artifact (SA) substantially decreases when a PE is used. The orientation of the stimulating current relative to the position of the targeted fibers (Schaffer collaterals) was controlled when using a PE. The use of PEs allowed the accurate recording of the physiological response that contains three clearly defined peaks. Stimulation can be elicited at PW as short as 30 micros when the main current is capacitive. The charge needed to elicit physiological responses was in the range of 1-40 nC (the lower values for the PE) suggesting that use of PEs is most advantageous for well-controlled microstimulation studies in brain slices.

A new fast electrophysiological response measured extracellularly in a mouse hippocampal brain slice.

In a hippocampal mouse brain slice the CA1 stratum radiatum field potential evoked by electrical stimulation of the Schaffer collaterals was used to analyze the very early responses. Parallel bipolar electrodes were utilized to lower the voltage induced by the stimulating current in the recording electrode, and to keep the induced voltage within the linear range of the headstage preamplifier and the recording amplifiers. When the stimulating and recording electrodes are in saline in the same plane and same depth, the shapes of the recorded voltage and stimulating current are similar. The shape of the recorded voltage significantly changes when the recording electrode is in the stratum radiatum of CA1. The signal recorded in the first 2 ms, before the presynaptic volley, indicates the existence of a fast response shown as a positive deflection. For times slightly longer than the stimulating pulse width, the fast response overlaps with the voltage induced by the discharging of the polarization charge accumulated in the double layer capacitance at the interface between metal and saline. For times longer than about 1.4 ms the fast response and presynaptic volley are superimposed. The fast response is about 0.5 mV when the stimulating charge is 15-25 nC. The demonstration that the fast response disappears upon bath perfusion of tetrodotoxin is convincing support for its axonal origin. We postulate that this fast response represents the current source corresponding to the Schaffer collaterals excitatory sink. An undistorted recording of the first 2 ms of the sweep gives useful information about the fast neuronal activity measured extracellularly, and cannot be regarded as a simple stimulus artifact.

Biphasic effects of angiotensin (1-7) and its interactions with angiotensin II in rat aorta.

Using isolated rat aortic rings perfused with Krebs-Henseleit saline, the vascular effects of angiotensin (1-7) (Ang [1-7]) and its interactions with angiotensin II (Ang II) were investigated. Ang (1-7) induced endothelium-dependent relaxation and vasodilating effects in preparations precontracted with phenylephrine. Without preconstriction, Ang (1-7) at high doses (10(-6) 10(-5) M) produced either a significant inhibition of Ang II-induced vasoconstriction or a non-tachyphylactic vasopressor response. While losartan inhibited the vasoconstriction induced by Ang (1-7), A779 blocked only its relaxation. Unlike losartan, blockade of AT(2)-receptors with PD 123319 had no effect. Taking into account the biphasic effects of angiotensin (1-7), we propose that it is one of the active components of the renin-angiotensin system, which is involved as a modulator both in the counter-regulatory actions of Ang II and in the self-regulation of its own vasodilating effects.

Pedunculopontine nucleus evoked potentials from subthalamic nucleus stimulation in Parkinson's disease.

The effects of subthalamic nucleus (STN) stimulation on the pedunculopontine nucleus area (PPNR) evoked activities were examined in two patients with Parkinson's disease. The patients had previously undergone bilateral STN deep brain stimulation (DBS) and subsequently received unilateral DBS electrodes in the PPNR. Evoked potentials were recorded from the local field potentials (LFP) from the PPNR with STN stimulation at different frequencies and bipolar contacts. Ipsilateral and contralateral short latency (<2ms) PPNR responses were evoked from left but not from right STN stimulation. In both patients, STN stimulation evoked contralateral PPNR responses at medium latencies between 41 and 45ms. Cortical evoked potentials to single pulse STN stimulation were observed at latencies between 18 and 27ms. These results demonstrate a functional connection between the STN and the PPNR. It likely involves direct projections between the STN and PPNR or polysynaptic pathways with thalamic or cortical relays.

Contribution of NMDA receptor-mediated component to the EPSP in mouse Schaffer collateral synapses under single pulse stimulation protocol.

The degree to which NMDA receptors contribute to hippocampal CA(1) stratum radiatum excitatory postsynaptic potentials (EPSP) is a matter of debate. This experiment was designed to resolve the issue by documenting and positively identifying the elements of the NMDA dependent component in the extracellularly recorded stratum radiatum CA(1) field potential under low stimulation conditions and in the presence of physiologic levels of Mg(2+). We show that EPSP generation consists of activation of both AMPA and NMDA receptor channels, which mediate distinct components of the recorded field potential. We propose that the EPSP is a combination of two waves rather than one, which sometimes has been attributed to the exclusive activation of AMPA channels. Our data suggest that the three recorded peaks signify different events. The first peak reflects the presynaptic volley while the other two represent the actual EPSP. The first peak of the EPSP is determined mainly by flow of ions through AMPA channels. The second peak most likely is determined by the concurrence of two phenomena: ionic flow through NMDA channels and the source corresponding to the sink generated at the cell bodies in the pyramidal layer. The NMDA dependent component was recorded when Mg(2+) was present in physiological concentrations. The presynaptic volley and second peak do not saturate over a 10-fold increase of the stimulation charge and their amplitudes are highly correlated. The first peak amplitude rapidly saturates. The sensitivity of the recorded signals is different, the first peak being the most sensitive (1.25-0.26 mV/nC). Isolation of NMDA dependent components under physiological conditions when using a single pulse low stimulation protocol would allow more precise investigations of the NMDA dependent forms of synaptic plasticity.