Distinct Aspects Research Articles

Light field reconstruction in angular domain with multi-models fusion through representation alternate convolution.

To alleviate the spatial-angular trade-off in sampled light fields (LFs), LF super-resolution (SR) has been studied. Most of the current LFSR methods only concern limited relations in LFs, which leads to the insufficient exploitation of the multi-dimensional information. To address this issue, we present a multi-models fusion framework for LFSR in this paper. Models embodying LF from distinct aspects are integrated to constitute the fusion framework. Therefore, the number and the arrangement of these models together with the depth of each model determine the performance of the framework; we make the comprehensive analysis on these factors to reach the best SR result. However, models in the framework are isolated to each other as the unique inputs are required. To tackle this issue, the representation alternate convolution (RAC) is introduced. As the fusion is conducted successfully through the RAC, the multi-dimensional information in LFs is fully exploited. Experimental results demonstrate that our method achieves superior performance against state-of-the-art techniques quantitatively and qualitatively.

Retinoic acid receptors at 35: molecular convergence of vitamin A and steroid hormone action

The fields of vitamins and steroid hormones emerged in parallel in the early parts of the twentieth century. Scientists in both fields were initially interested in the purification of natural compounds present respectively in food stuff and extracts from organs and biological fluids that had profound effects on reproduction, development, and general maintenance of a healthy organism. Coincidently, the chemical structure of vitamin A and the steroid hormones oestradiol and progesterone were resolved around the same time in the mid 1930s. From these early common grounds, the fields of vitamin A and steroid hormones then diverged into their respective branches of biological sciences, mainly nutrition/vision and endocrinology for the next several decades. Yet, 50 years later, it is the surprising discovery that retinoic acid (RA), an active metabolite of vitamin A, exerts its biological effects via a member of the superfamily of steroid receptors that led to the improbable reunification of vitamin A and steroid hormones action. We celebrate the scientific milestone of the discovery of the retinoic acid receptor (RAR) with a special issue of the Journal of Molecular Endocrinology. This issue comprises chronicles reminiscing how that discovery was achieved independently by two young Canadian scientists working in the laboratories of Ronald Evans and Pierre Chambon separated by a continent and an ocean, and reviews by international experts describing distinct aspects of RAR-dependent biology and mode of action.

Post-encoding modulation of spatial memory consolidation by propofol.

Memory consolidation is a continuous transformative process between encoding and retrieval of mental representations. Recent research has shown that neural activity immediately after encoding is particularly associated with later successful retrieval. It is currently unclear whether post-encoding neural activity makes a distinct and causal contribution to memory consolidation. Here, we investigated the role of the post-encoding period for consolidation of spatial memory in neurologically normal human subjects. We used the GABAA-ergic anesthetic propofol to transiently manipulate neural activity during the initial stage of spatial memory consolidation without affecting encoding or retrieval. A total of 52 participants undergoing minor surgery learned to navigate to a target in a five-armed maze derived from animal experiments. Participants completed learning either immediately prior to injection of propofol (early group) or more than 60min before injection (late group). Four hours after anesthesia, participants were tested for memory-guided navigation. Our results show a selective impairment of navigation in the early group and near-normal performance in the late group. Analysis of navigational error patterns further suggested that propofol impaired distinct aspects of spatial representations, in particular sequences of path segments and spatial relationships between landmarks. We conclude that neural activity during the post-encoding period makes a causal and specific contribution to consolidation of representations underlying self-centered and world-centered memory-guided navigation. Distinct aspects of these representations are susceptible to GABAA-ergic modulation within a post-encoding time-window of less than 60min, presumably reflecting associative processes that contribute to the formation of integrated spatial representations that guide future behavior.

Neural Networks Implicated in Autobiographical Memory Training.

Training of autobiographical memory has been proposed as an intervention to improve cognitive function. The neural substrates for such improvements are poorly understood. Several brain areas have been previously linked to autobiographical recollection, including structures in the default mode network (DMN) and the sensorimotor network. Here, we tested the hypothesis that changes in connectivity within different neural networks support distinct aspects of memory improvement in response to training on a group of 59 human subjects. We found that memory training using olfactory cues increases resting-state intranetwork DMN connectivity, and this associates with improved recollection of cue-specific memories. On the contrary, training decreased resting-state connectivity within the sensorimotor network, a decrease that correlated with improved ability for voluntary recall. Moreover, preliminary data indicate that only the decrease in sensorimotor connectivity associated with the training-induced decrease in the tumor necrosis factor α (TNFα) factor, an immune modulation previously linked to improved cognitive performance. We identified functional and biochemical factors that associate with distinct memory processes improved by autobiographical training. Pathways which connect autobiographical memory with both high-level cognition and somatic physiology are discussed.

Hyper-excitability of corticothalamic PT neurons in mPFC promotes irritability in the mouse model of Alzheimer's disease.

Neuropsychiatric symptoms in patients with Alzheimer's disease (AD) are presented as early as the mild cognitive impairment (MCI) stage. However, it remains unclear whether separate neuronal populations encode distinct aspects of the neuropsychiatric symptoms and drive them differently. Here, we report that pyramidal tract (PT) neurons projecting to the thalamus, but not to the pons or medulla, in the medial prefrontal cortex (mPFC) of the mouse model of AD show increased excitability, which is associated with increased irritability and aggressivity. Decreased Kv6.3 in corticothalamic PT neurons contributes to hyper-excitability, which is tightly associated with aggressive behaviors. Overexpression of Kv6.3 not only prevents abnormal excitability of corticothalamic PT neurons in mPFC, but also rescues aggressive behaviors of 3xTg model mice. Our study provides causal evidence for the contribution of corticothalamic PT neurons to irritability in the 3xTg model of AD and reveals circuit mechanisms used by PT neurons to regulate neuropsychiatric symptoms in AD.

Evidence for independent representational contents in inhibitory control subprocesses associated with frontoparietal cortices.

Inhibitory control processes have intensively been studied in cognitive science for the past decades. Even though the neural dynamics underlying these processes are increasingly better understood, a critical open question is how the representational dynamics of the inhibitory control processes are modulated when engaging in response inhibition in a relatively automatic or a controlled mode. Against the background of an overarching theory of perception-action integration, we combine temporal and spatial EEG signal decomposition methods with multivariate pattern analysis and source localization to obtain fine-grained insights into the neural dynamics of the representational content of response inhibition. For this purpose, we used a sample of N= 40 healthy adult participants. The behavioural data suggest that response inhibition was better in a more controlled than a more automated response execution mode. Regarding neural dynamics, effects of response inhibition modes relied on a concomitant coding of stimulus-related information and rules of how stimulus information is related to the appropriate motor programme. Crucially, these fractions of information, which are encoded at the same time in the neurophysiological signal, are based on two independent spatial neurophysiological activity patterns, also showing differences in the temporal stability of the representational content. Source localizations revealed that the precuneus and inferior parietal cortex regions are more relevant than prefrontal areas for the representation of stimulus-response selection codes. We provide a blueprint how a concatenation of EEG signal analysis methods, capturing distinct aspects of neural dynamics, can be connected to cognitive science theory on the importance of representations in action control.

The impact of textual enhancement and frequency manipulation on incidental learning of collocations from reading

Collocational knowledge is central to communicative competence, but many second language (L2) learners struggle to acquire this aspect. To address this limitation, the present study investigated if textual enhancement and frequency manipulation would affect incidental learning of collocations from reading. Fifty-four first language (L1) Cantonese speakers read two English stories in which 12 adjective–pseudonoun collocations appeared either three or six times. The target collocations were coloured in red under the enhanced condition. Participants’ attentional processes were examined using their eye-movements during reading and stimulated recall comments prompted by their own eye-movements. After reading, unannounced immediate and delayed posttests were administered. The results showed that increased frequency led to greater visual attention to the target collocations in terms of both duration and counts of eye-fixations. Increased frequency further led to better performances on the immediate form and collocation recognition tests. The effects of colouring increased first fixation durations, only when the target collocations appeared six times. Colouring was also linked to higher immediate collocation recognition and delayed meaning recognition and collocation recall scores. Stimulated recall comments revealed that participants noticed the pseudonouns and sometimes utilized their collocate adjectives to infer the meaning of the pseudonouns. The findings of this study demonstrate that textual enhancement and frequency manipulation may affect distinct aspects of collocational learning.

Seeing others’ side to serve: Understanding how and when servant leadership impacts employee knowledge-hiding behaviors

Previous studies have overlooked critical differences between different aspects of employees’ knowledge-hiding behaviors. Using Social Information Processing theory as an anchor, we fill this void by investigating the impact of servant leadership on three distinct aspects of employees’ knowledge-hiding behaviors: evasive hiding, playing dumb, and rationalized hiding. Specifically, we propose that servant leadership is negatively related to evasive hiding and playing dumb, and yet, paradoxically, positively related to rationalized hiding. We further propose employee perspective taking as a crucial underlying mechanism and employee justice orientation as a relevant boundary condition of the hypothesized relationships between servant leadership and employees’ knowledge-hiding behaviors. Our time-lagged and two-source data provide support for our hypotheses. The theoretical and practical implications of our findings are discussed.

On the Embodiment of Social Cognition Skills: The Inner and Outer Body Processing Differently Contributes to the Affective and Cognitive Theory of Mind.

A specific interpretation of embodiment assigns a central role to the body representations (BR) in cognition. In the social cognition domain, BR could be pivotal in representing others' actions and states. However, empirical evidence on the relationship between different BR and social cognition, in terms of Theory of Mind (ToM), in the same sample of participants is missing. Here, this relationship was explored considering individual differences in the action-oriented BR (aBR), nonaction-oriented BR (NaBR), and subjective predisposition toward internal bodily sensations (interoceptive sensibility, ISe). Eighty-two healthy adults were given behavioral measures probing aBR, NaBR, ISe, and affective/cognitive ToM. The results suggest that NaBR, which mainly relies on exteroceptive signals, predicts individual differences in cognitive ToM, possibly because it can allow differentiating between the self and others. Instead, the negative association between affective ToM and ISe suggests that an alteration of the internal body state representation (i.e., over-reporting interoceptive sensations) can affect emotional processing in social contexts. The finding that distinct aspects of the body processing from within (ISe) and from the outside (NaBR) differently contribute to ToM provides empirical support to the BR role in social cognition and can be relevant for developing interventions in clinical settings.

Behavioural phenotypes of intrinsic motivation in schizophrenia determined by cluster analysis of objectively quantified real-world performance

Intrinsic motivation deficits are a prominent feature of schizophrenia that substantially impacts functional outcome. This study used cluster analysis of innate real-world behaviours captured during two open-field tasks to dimensionally examine heterogeneity in intrinsic motivation in schizophrenia patients (SZ) and healthy controls (HC). Wireless motion capture quantified participants’ behaviours aligning with distinct aspects of intrinsic motivation: exploratory behaviour and effortful activity in the absence of external incentive. Cluster analysis of task-derived measures identified behaviourally differentiable subgroups, which were compared across standard clinical measures of general amotivation, cognition, and community functioning. Among 45 SZ and 47 HC participants, three clusters with characteristically different behavioural phenotypes emerged: low exploration (20 SZ, 19 HC), low activity (15 SZ, 8 HC), and high exploration/activity (10 SZ, 20 HC). Low performance in either dimension corresponded with similar increased amotivation. Within-cluster discrepancies emerged for amotivation (SZ > HC) within the low exploration and high performance clusters, and for functioning (SZ < HC) within all clusters, increasing from high performance to low activity to low exploration. Objective multidimensional characterization thus revealed divergent behavioural expression of intrinsic motivation deficits that may be conflated by summary clinical measures of motivation and overlooked by unidimensional evaluation. Deficits in either aspect may hinder general motivation and functioning particularly in SZ. Multidimensional phenotyping may help guide personalized remediation by discriminating between intrinsic motivation impairments that require amelioration versus unimpaired tendencies that may facilitate remediation.

Quantum memory-assisted entropic uncertainty and entanglement dynamics: two qubits coupled with local fields and Ornstein Uhlenbeck noise

Entropic uncertainty and entanglement are two distinct aspects of quantum mechanical procedures. The estimation of the entropic uncertainty is required for the increased accuracy and, hence, for the enhanced efficacy of quantum information processing tasks. In this regard, we analyze the entropic uncertainty, entropic uncertainty lower bound, and concurrence dynamics in two non-interacting qubits. The exposure of two qubits is studied in two different qubit-noise configurations, namely, common qubit-noise and independent qubit-noise interactions. To include the noisy effects of the local external fields, a Gaussian Ornstein–Uhlenbeck process is considered. We show that the increase in entropic uncertainty gives rise to the disentanglement in the two-qubit Werner state. Depending on the parameters adjustment and the number of environments coupled, different classical environments have varying capacities to induce entropic uncertainty and disentanglement in quantum systems. The entanglement remains vulnerable to the external classical fields; however, by employing the ideal parameter ranges we provided, prolonged entanglement retention while preventing entropic uncertainty growth can be achieved. Besides, we have also analyzed the intrinsic behavior of the classical fields towards two-qubit entanglement with no imperfection with respect to different parameters.

Comparison of quantitative ultrasonography and dual X-ray absorptiometry for bone status assessment in South African children living with HIV.

Children living with HIV (CLHIV) have decreased bone mineral content (BMC) and density (BMD), increasing risk for fracture and future osteoporosis. While DXA is the gold-standard for bone assessments, it lacks availability in resource-constrained settings (RCS). Quantitative ultrasound (QUS) offers an alternative owing to its portability, low cost, ease of handling, and lack of ionizing radiation. While QUS has detected reduced bone quality in CLHIV, the relationship between QUS and DXA in this population remains unexplored. At baseline and 12 months, BMC and BMD of the whole body, lumbar spine, and radius were measured by DXA in a longitudinal cohort of CLHIV in Johannesburg, South Africa. Calcaneal speed of sound (SOS) and broadband ultrasound attenuation (BUA) and radius SOS were obtained by QUS, and calcaneal stiffness index (SI) was calculated. Spearman correlations, with and without HIV stratification, were performed between QUS and DXA measurements at each visit and for absolute difference in measurements between visits. At baseline and 12-months, calcaneal BUA and SI displayed strong positive correlations with DXA, with only modest correlations between radial QUS and DXA at baseline. Longitudinal measures of QUS did not correlate with DXA. At both baseline and 12-months, individuals with DXA whole-body BMD z-score < -1 displayed significantly lower calcaneal BUA and SI. Cross-sectionally, calcaneal QUS correlates strongly with whole body DXA and may represent a viable diagnostic alternative in RCS. Longitudinally, the two methods do not correlate well, possibly reflecting that each method assesses distinct aspects of bone architecture.

Imagetic and affective measures of memory reverberation diverge at sleep onset in association with theta rhythm

The ‘day residue’ - the presence of waking memories into dreams - is a century-old concept that remains controversial in neuroscience. Even at the psychological level, it remains unclear how waking imagery cedes into dreams. Are visual and affective residues enhanced, modified, or erased at sleep onset? Are they linked, or dissociated? What are the neural correlates of these transformations? To address these questions we combined quantitative semantics, sleep EEG markers, visual stimulation, and multiple awakenings to investigate visual and affect residues in hypnagogic imagery at sleep onset. Healthy adults were repeatedly stimulated with an affective image, allowed to sleep and awoken seconds to minutes later, during waking (WK), N1 or N2 sleep stages. ‘Image Residue’ was objectively defined as the formal semantic similarity between oral reports describing the last image visualized before closing the eyes (‘ground image’), and oral reports of subsequent visual imagery (‘hypnagogic imagery). Similarly, ‘Affect Residue’ measured the proximity of affective valences between ‘ground image’ and ‘hypnagogic imagery’. We then compared these grounded measures of two distinct aspects of the ‘day residue’, calculated within participants, to randomly generated values calculated across participants. The results show that Image Residue persisted throughout the transition to sleep, increasing during N1 in proportion to the time spent in this stage. In contrast, the Affect Residue was gradually neutralized as sleep progressed, decreasing in proportion to the time spent in N1 and reaching a minimum during N2. EEG power in the theta band (4.5-6.5 Hz) was inversely correlated with the Image Residue during N1. The results show that the visual and affective aspects of the ‘day residue’ in hypnagogic imagery diverge at sleep onset, possibly decoupling visual contents from strong negative emotions, in association with increased theta rhythm.

FMRI BOLD and MEG theta power reflect complementary aspects of activity during lexicosemantic decision in adolescents with ASD

Neuroimaging studies of autism spectrum disorder (ASD) have been predominantly unimodal. While many fMRI studies have reported atypical activity patterns for diverse tasks, the MEG literature in ASD remains comparatively small. Our group recently reported atypically increased event-related theta power in individuals with ASD during lexicosemantic processing. The current multimodal study examined the relationship between fMRI BOLD signal and anatomically-constrained MEG (aMEG) theta power. Thirty-three adolescents with ASD and 23 typically developing (TD) peers took part in both fMRI and MEG scans, during which they distinguished between standard words (SW), animal words (AW), and pseudowords (PW). Regions-of-interest (ROIs) were derived based on task effects detected in BOLD signal and aMEG theta power. BOLD signal and theta power were extracted for each ROI and word condition. Compared to TD participants, increased theta power in the ASD group was found across several time windows and regions including left fusiform and inferior frontal, as well as right angular and anterior cingulate gyri, whereas BOLD signal was significantly increased in the ASD group only in right anterior cingulate gyrus. No significant correlations were observed between BOLD signal and theta power. Findings suggest that the common interpretation of increases in BOLD signal and theta power as ‘activation’ require careful differentiation, as these reflect largely distinct aspects of regional brain activity. Some group differences in dynamic neural processing detected with aMEG that are likely relevant for lexical processing may be obscured by the hemodynamic signal source and low temporal resolution of fMRI.

Crystal Structure Optimization with Deep-Autoencoder-Based Intrusion Detection for Secure Internet of Drones Environment

Drone developments, especially small-sized drones, usher in novel trends and possibilities in various domains. Drones offer navigational inter-location services with the involvement of the Internet of Things (IoT). On the other hand, drone networks are highly prone to privacy and security risks owing to their strategy flaws. In order to achieve the desired efficiency, it is essential to create a secure network. The purpose of the current study is to have an overview of the privacy and security problems that recently impacted the Internet of Drones (IoD). An Intrusion Detection System (IDS) is an effective approach to determine the presence of intrusions in the IoD environment. The current study focuses on the design of Crystal Structure Optimization with Deep-Autoencoder-based Intrusion Detection (CSODAE-ID) for a secure IoD environment. The aim of the presented CSODAE-ID model is to identify the occurrences of intrusions in IoD environment. In the proposed CSODAE-ID model, a new Modified Deer Hunting Optimization-based Feature Selection (MDHO-FS) technique is applied to choose the feature subsets. At the same time, the Autoencoder (AE) method is employed for the classification of intrusions in the IoD environment. The CSO algorithm, inspired by the formation of crystal structures based on the lattice points, is employed at last for the hyperparameter-tuning process. To validate the enhanced performance of the proposed CSODAE-ID model, multiple simulation analyses were performed and the outcomes were assessed under distinct aspects. The comparative study outcomes demonstrate the superiority of the proposed CSODAE-ID model over the existing techniques.

PON2 mediates mitochondrial dysfunction in tracheal epithelial cells in response to a quorum sensing molecule N-(-3-oxododecanoyl)-l-homoserine lactone.

The opportunistic bacterium Pseudomonas aeruginosa secretes the quorum-sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (C12) to co-ordinate gene expression profiles favorable for infection. Recent studies have demonstrated that high concentrations of C12 impair many aspects of host cell physiology, including mitochondrial function and cell viability. The cytotoxic effects of C12 are mediated by the lactonase enzyme, Paraoxonase 2 (PON2), which hydrolyzes C12 to a reactive metabolite. However, the influence of C12 on host cell physiology at concentrations observed in patients infected with P. aeruginosa is largely unknown. Since the primary site of P. aeruginosa infections is the mammalian airway, we sought to investigate how PON2 modulates the effects of C12 at subtoxic concentrations using immortalized murine tracheal epithelial cells (TECs) isolated from wild-type (WT) or PON2-knockout (PON2-KO) mice. Our data reveal that C12 at subtoxic concentrations disrupts mitochondrial bioenergetics to hinder cellular proliferation in TECs expressing PON2. Subtoxic concentrations of C12 disrupt normal mitochondrial network morphology in a PON2-dependent manner without affecting mitochondrial membrane potential. In contrast, higher concentrations of C12 depolarize mitochondrial membrane potential and subsequently trigger caspase signaling and apoptotic cell death. These findings demonstrate that different concentrations of C12 impact distinct aspects of host airway epithelial cell physiology through PON2 activity in mitochondria.

Optimal weighted fusion based insider data leakage detection and classification model for Ubiquitous computing systems

With the rapid growth and evolving advancement in artificial technology, Ubiquitous computing methods plays a vital role in day to day lives. Insider threats were malicious activities which are executed by an official worker within an institution. Insider threats indicate cybersecurity challenges for public and private companies, as an insider attack could cause widespread damages to company properties than exterior attacks. Many prevailing methods in the domain of insider threat concentrated on identifying general insider attack situations. But insider attacks are takes place in several ways, and one of the dangerous attack is a data leakage attack which is accomplished by a malicious insider before one leaves a company. This article develops a Metaheuristic with Weighted Fusion Based Insider Data Leakage Detection and Classification (MWF-IDLDC) Model for Ubiquitous Computing Systems. The presented MWF-IDLDC technique primarily performs pre-processing and feature extraction at the initial stage. In addition, the MWF-IDLDC technique derives a weighted fusion-based feature extraction approach comprising three DL methods namely long short-term memory (LSTM), gated recurrent unit (GRU), and stacked autoencoder (SAE). For optimally tuning the hyperparameters related to the DL models, the ant lion optimizer (ALO) algorithm is utilized in this study. The design of fusion process with ALO hyperparameter optimizer demonstrate the novelty of the work. The experimental validation of the MWF-IDLDC approach can be tested using a series of simulations and the outcomes were scrutinized under distinct aspects. The comparative analysis highlighted the improvements of the MWF-IDLDC method compared to recent approaches with maximum accuracy of 99.40%.

Microbiome epidemiology and association studies in human health.

Studies of the human microbiome share both technical and conceptual similarities with genome-wide association studies and genetic epidemiology. However, the microbiome has many features that differ from genomes, such as its temporal and spatial variability, highly distinct genetic architecture and person-to-person variation. Moreover, there are various potential mechanisms by which distinct aspects of the human microbiome can relate to health outcomes. Recent advances, including next-generation sequencing and the proliferation of multi-omic data types, have enabled the exploration of the mechanisms that connect microbial communities to human health. Here, we review the ways in which features of the microbiome at various body sites can influence health outcomes, and we describe emerging opportunities and future directions for advanced microbiome epidemiology.

Measuring context-specific collectivism: The Metzian Ubuntu Inventory

Cultural values are often used to categorise groups, e.g. individualism versus collectivism. Often when cultural values are measured, etic scales are used without giving attention to cultural value nuances, e.g. different types of collectivism. An example of a nuanced cultural value is found in the interpretation of ubuntu as a context-specific presentation of collectivism in South Africa. In this article, which may be viewed as an instance of experimental philosophy, the concept of ubuntu will be introduced based on the work of the philosopher Thaddeus Metz by focusing on the distinct aspects of harmonious relationships of identity and solidarity. The theoretical basis was used to develop and validate the Metzian Ubuntu Inventory (MUI) with a sample of 316 respondents. This scale consists of nine items, and has reliability and validity in the South African context. In the conclusion, possible applications of the MUI are suggested.

Robotics and cochlear implant surgery: goals and developments

Cochlear implantation (CI) is a viable option for patients with severe sensorineural hearing loss. Advances in CI have focused on minimizing cochlear trauma to improve hearing preservation outcomes, and in doing so expanding candidacy to patients with useful cochlear reserve. Robotics holds promise as a potential tool to minimize intracochlear trauma with electrode insertion, improve surgical efficiency, and reduce surgical complications. The purpose of this review is to summarize efforts and advances in the field of robotic-assisted CI. Work on robotics and CI over the past few decades has explored distinct surgical aspects, including image-based surgical planning and intraoperative guidance, minimally invasive robotic-assisted approaches mainly through percutaneous keyhole direct cochlear access, robotic electrode insertion systems, robotic manipulators, and drilling feedback control through end effector sensors. Feasibility and safety have been established and many devices are undergoing clinical trials for clinical adoption, with some having already achieved approval of national licensing bodies. Significant work has been done over the past two decades that has shown robotic-assisted CI to be feasible and safe. Wider clinical adoption can potentially result in improved hearing preservation and quality of life outcomes to more CI candidates.