Perception Of Signals Research Articles

COL2-dependent photoperiodic floral induction in Nicotiana sylvestris seems to be lost in the N. sylvestris × N. tomentosiformis hybrid N. tabacum.

Plants are sessile organisms that maximize reproductive success by adapting to their environment. One of the key steps in the reproductive phase of angiosperms is flower development, requiring the perception of multiple endogenous and exogenous signals integrated via a complex regulatory network. Key floral regulators, including the main transcription factor of the photoperiodic pathway (CONSTANS, CO) and the central floral pathway integrator (FLOWERING LOCUS T, FT), are known in many species. We identified several CO-like (COL) proteins in tobacco (Nicotiana tabacum). The NtCOL2a/b proteins in the day-neutral plant N.tabacum were most closely related to Arabidopsis CO. We characterized the diurnal expression profiles of corresponding genes in leaves under short-day (SD) and long-day (LD) conditions and confirmed their expression in phloem companion cells. Furthermore, we analyzed the orthologs of NtCOL2a/b in the maternal LD ancestor (N. sylvestris) and paternal, facultative SD ancestor (N.tomentosiformis) of N. tabacum and found that they were expressed in the same diurnal manner. NtCOL2a/b overexpression or knock-out using the CRISPR/Cas9 system did not support a substantial role for the CO homologs in the control of floral transition in N. tabacum. However, NsCOL2 overexpression induced flowering in N. sylvestris under typically non-inductive SD conditions, correlating with the upregulation of the endogenous NsFTd gene. Our results suggest that NsFTd is transcriptionally regulated by NsCOL2 and that this COL2-dependent photoperiodic floral induction seems to be lost in N. tabacum, providing insight into the diverse genetics of photoperiod-dependent flowering in different Nicotiana species.

A Rydberg atom-based amplitude-modulated receiver using the dual-tone microwave field

We propose a Rydberg atom-based receiver for amplitude-modulation (AM) reception utilizing a dual-tone microwave field. The pseudo-random binary sequence (PRBS) signal is encoded in the basic microwave field (B-MW) at the frequency of 14.23 GHz. The signal can be decoded by the atomic receiver itself but more obvious with the introduction of an auxiliary microwave (A-MW) field. The receiver’s amplitude variations corresponding to microwave field are simulated by solving density matrices to give this mechanism theoretical support. An appropriate AM frequency is obtained by optimizing the signal-to-noise ratio, guaranteeing both large data transfer capacity (DTC) and high fidelity of the receiver. The power of two MW fields, along with the B-MW field frequency, is studied to acquire larger DTC and wider operating bandwidth. Finally, the readout of PRBS signals is performed by both the proposed and conventional mechanisms, and the comparison proves the obvious increment of DTC with the proposed scheme. This proof-of-principle demonstration exhibits the potential of the dual-tone scheme and offers a novel pathway for Rydberg atom-based microwave communication, which is beneficial for long-distance communication and weak signal perception outside the laboratory.

Maternal perception of hunger-satiety signals and their impact on feeding and nutritional status of infants in Mexico

nutrition during the first two years of life is crucial for the physical, cognitive, and emotional development of children. This study aimed to: 1) associate maternal perception of hunger and satiety signals with the type of feeding; 2) associate maternal perception of hunger and satiety signals with the infant's weight status; and 3) determine the influence of feeding type on the infant's BMI-for-age. a descriptive correlational cross-sectional study was conducted with 424 mother-infant dyads in Sinaloa, Mexico, using systematic random sampling. Mothers completed questionnaires on feeding practices and perception of hunger and satiety signals. Anthropometric data of the infant were measured, and the influence of feeding type on the infant's BMI-for-age z-score was analyzed using multiple linear regression. 45.8 % of mothers reported a low perception of hunger and satiety signals. 30.2 % of infants were overweight. Mothers with a high perception of signals reported a lower proportion of overweight infants. Mixed feeding and early introduction of complementary foods significantly influence the increase in infant zIMC/age score. maternal perception of hunger and satiety signals influences the infant's weight status. Mixed feeding and early introduction of complementary foods increase the risk of overweight in infants. It is crucial to promote adequate perception of these signals to prevent nutritional problems in early childhood.

Bi-Manual Sensory Discrimination: A Kinesthetic Study.

The ability of humans to perceive and differentiate kinesthetic sensory information significantly influences our daily activities and motor control. This study examines the impact of asynchronous bi-manual discrimination tasks compared to uni-manual discrimination tasks on kinesthetic perception. Our study aims to reveal the relationship between kinesthetic perception of haptic signals by examining perceptual thresholds in three different scenarios using (i) the dominant hand, (ii) the non-dominant hand, and (iii) both hands simultaneously to differentiate between two successive signals. Subjects exposed to force signals in these three situations conveyed their perceptions of alterations in signal magnitude after each trial. Subsequently, we applied psychometric functions to the collected responses to determine perceptual thresholds. Our results indicate a substantial difference in threshold values between bi-manual and uni-manual scenarios, with the bi-manual scenario exhibiting higher thresholds, indicating inferior perceptual ability when both hands are simultaneously utilized in two separate discrimination tasks. Furthermore, our investigation reveals distinct perception thresholds between the dominant and non-dominant hands, owing to differences in the perceptual capability of the two hands. These findings provide substantial insight into how the nature of tasks may alter kinesthetic perception, offering implications for the development of haptic interfaces in practical applications.

Analysis Of Factors Affecting Bird Identification Mechanisms and Suggestions for Environmental Protection

Recognition, happening between species, kin, neighbors, and mates, is the basis of most animal interactions such as mating, food provisioning, and territory protection. The identification accuracy of conspecifics is facilitated by some factors but impeded by others, such as the cost of acquiring and memorizing social information. Avians primarily use vocal and visual identity signals to recognize other individuals, such as the general song characteristics or spot patterns on the feathers. By analyzing the identification context, signature production, and signal perception and response, the article reviews recent works to recommend environmental conservation approaches from the perspective of bird identification. Factors including sex, behavioral context, vocalization types, distance, and cognitive cost are demonstrated in their influence on recognition, and the lack of research on visual recognition does not indicate the more adaptive and complex nature of vocal recognition. Furthermore, the review encourages reducing anthropogenic effects on noise, light, and climate; avoiding behavioral disturbance; and restoring natural habitats. The review provides insights into the current state of individual animal recognition research by organizing the main findings of recent studies.

Bacterial biofilm formation and anti-biofilm strategies

Bacteria are ubiquitous prokaryotes. They are involved in biofilm formation and also have the ability to produce anti-biofilm products for biofilm mitigation. This special issue entitled: “Biofilms- community structure, applications and mitigation” of the journal Research in Microbiology was designed to discuss the flexibility of bacterial biofilms and their products under particular circumstances. Given that quorum sensing (QS) controls biofilm growth in some situations, especially for pathogenic bacteria antibiotic evading strategies. In Gram-negative bacteria, N-acyl homoserine lactones are the major quorum sensing signaling molecules. Another approach to prevent bacterial biofilm formation may be to inhibit the QS-regulated activities using quorum quenching (QQ). In this context, QS inhibitors and QS enzymes are important because they, respectively, interfere with signal creation, perception, or degradation and chemical modification. There have been numerous reports of QQ enzymes from bacteria. Treatment failure and recurrent staphylococcal infections are also brought on by biofilm development, which boosts an organism's ability to withstand antibiotics and is thought to be a virulence factor in patients. However, polyphenol quercetin antibiofilm activity is naturally available against drug-resistant Staphylococcus aureus.

A Wearable Co-Located Neural-Mechanical Signal Sensing Device for Simultaneous Bimodal Muscular Activity Detection.

The co-located and concurrent measurement of both muscular neural activity and muscular deformation is considered necessary in many applications, such as medical robotics, assistive exoskeletons and muscle function evaluations. Nevertheless, conventional muscle-related signal perception systems either detect only one of these modalities, or are made with rigid and bulky components that cannot provide conformal and flexible interface. Herein, a flexible, easy-to-fabricate, bimodal muscular activity sensing device, which collects neural and mechanical signal at the same muscle location, is reported. The sensing patch includes a screen-printed sEMG sensor, and a pressure-based muscular deformation sensor (PMD sensor) based on a highly sensitive, co-planar iontronic pressure sensing unit. Both sensors are integrated on a super-thin (25 μm) substrate. The sEMG sensor shows a high signal-to-noise ratio of 37.1 dB, and the PMD sensor sensor exhibits a high sensitivity of 70.9 kPa -1. The responses of the sensor to three types of muscle activities (isotonic, isometric, and passive stretching) were analyzed and validated by ultrasound imaging. Bimodal signals during dynamic walking experiments with different level-ground walking speeds were also investigated. The application of the bimodal sensor was verified in gait phase estimation, and results show that the assembly of both modalities significantly reduce (p < 0.05) the average estimation error across all subjects and all walking speeds to 3.82%. Demonstrations show the potential of this sensing device for informative evaluation of muscular activities, and its abilities in human-robot interaction.

A Psychoacoustic Quality Criterion for Path-Traced Sound Propagation.

In developing virtual acoustic environments, it is important to understand the relationship between the computation cost and the perceptual significance of the resultant numerical error. In this paper, we propose a quality criterion that evaluates the error significance of path-tracing-based sound propagation simulators. We present an analytical formula that estimates the error signal power spectrum. With this spectrum estimation, we can use a modified Zwicker's loudness model to calculate the relative loudness of the error signal masked by the ideal output. Our experimental results show that the proposed criterion can explain the human perception of simulation error in a variety of cases.

Comparison of methods for cardiac interoception self-assessment

Aim. Interoception reflects the perception, integration and modulation of visceral signals. Currently, there is no established universal approach to cardiac interoception assessment allowing its inclusion in the diagnostic protocol for various diseases. The aim was to compare three tests of interoception self-assessment based on heart palpitations within one day in healthy subjects.Material and methods. Eighty healthy volunteers took part in the study. To assess cardiac interoception, a test with button pushes at the moment of palpitations, a feedback test in the form of synchronous and asynchronous sound signals, a heartbeat counting task at specified time intervals were conducted with simultaneous electrocardiographic recording. The obtained data were compared with each other (Wilcoxon test). Its pairwise dependence (Spearman coefficient) and dependence on body parameters (sex, age, body mass index, fat mass, anxiety) were assessed (univariate linear regression).Results. The accuracy of the heartbeat counting task turned out to be significantly higher than in the button- pressing test (p=0,005). However, both estimates correlate with each other (r=0,66, p=0,003). A positive dependence of test accuracy on sex was found for the heartbeat counting task (p=0,021) and a negative dependence on fat mass for button- pressing task (p=0,032).Conclusion. The study found that volunteers' estimates of heartbeat accuracy varied across tests and were also associated with sex and body composition. The heart rate counting task and the button- pressing task are the most suitable for interoception assessment.

ViWise: Fusing Visual and Wireless Sensing Data for Trajectory Relationship Recognition

People usually form a social structure (e.g., a leader-follower, companion, or independent group) for better interactions among them and thus share similar perceptions of visible scenes and invisible wireless signals encountered while moving. Many mobility-driven applications have paid much attention to recognizing trajectory relationships among people. This work models visual and wireless data to quantify the trajectory similarity between a pair of users. We design a visual and wireless sensor fusion system, called ViWise, which incorporates the first-person video frames collected by a wearable visual device and the wireless packets broadcast by a personal mobile device for recognizing finer-grained trajectory relationships within a mobility group. When people take similar trajectories, they usually share similar visual scenes. Their wireless packets observed by ambient wireless base stations (called wireless scanners in this work) usually contain similar patterns. We model the visual characteristics of physical objects seen by a user from two perspectives: micro-scale image structure with pixel-wise features and macro-scale semantic context. However, we model characteristics of wireless packets based on the encountered wireless scanners along the user’s trajectory. Given two users’ trajectories, their trajectory characteristics behind the visible video frames and invisible wireless packets are fused together to compute the visual-wireless data similarity that quantifies the correlation between trajectories taken by them. We exploit modeled visual-wireless data similarity to recognize the social structure within user trajectories. Comprehensive experimental results in indoor and outdoor environments show that the proposed ViWise is robust in trajectory relationship recognition with an accuracy of above 90%.

Receptor-like kinases OsRLK902-1 and OsRLK902-2 form immune complexes with OsRLCK185 to regulate rice blast resistance.

Receptor-like kinases (RLKs) are major regulators of the plant immune response and play important roles in the perception and transmission of immune signals. RECEPTOR LIKE KINASE 902 (RLK902) is at the key node in leucine-rich repeat receptor-like kinase interaction networks and positively regulates resistance to the bacterial pathogen Pseudomonas syringae in Arabidopsis. However, the function of RLK902 in fungal disease resistance remains obscure. In this study, we found that the expression levels of OsRLK902-1 and OsRLK902-2, encoding two orthologues of RLK902 in rice, were induced by Magnaporthe oryzae, chitin, and flg22 treatment. osrlk902-1 and osrlk902-2 knockout mutants displayed enhanced susceptibility to M. oryzae. Interestingly, the osrlk902-1 rlk902-2 double mutant exhibited similar disease susceptibility, hydrogen peroxide production, and callose deposition to the two single mutants. Further investigation showed that OsRLK902-1 interacts with and stabilizes OsRLK902-2. The two OsRLKs form a complex with OsRLCK185, a key regulator in chitin-triggered immunity, and stabilize it. Taken together, our data demonstrate that OsRLK902-1 and OsRLK902-2, as well as OsRLCK185 function together in regulating disease resistance to M. oryzae in rice.

A tug-of-war to control plant emission of an airborne alarm signal

Aphids represent a major threat to crops. Hundreds of different viruses are aphid-borne. Upon aphid attack, plants release volatile organic compounds (VOCs) as airborne alarm signals to turn on the airborne defense (AD) of neighboring plants, thereby repelling aphids as well as reducing aphid fitness and virus transmission. This phenomenon provides a critical community-wide plant protection to fend off aphids, but the underlying molecular basis remains undetermined for a long time. In a recent article, Gong et al. established the NAC2-SAMT1 module as the core component regulating the emission of methyl-salicylate (MeSA), a major component of VOCs in aphid-attacked plants. Furthermore, they showed that SABP2 protein is critical for the perception of volatile MeSA signal by converting MeSA to Salicylic Acid (SA), which is the cue to elicit AD against aphids at the community level. Moreover, they showed that multiple viruses use a conserved glycine residue in the ATP-dependent helicase domain in viral proteins to shuttle NAC2 from the nucleus to the cytoplasm for degradation, leading to the attenuation of MeSA emission and AD. These findings illuminate the functional roles of key regulators in the complex MeSA-mediated airborne defense process and a counter-defense mechanism used by viruses, which has profound significance in advancing the knowledge of plant-pathogen interactions as well as providing potential targets for gene editing-based crop breeding.

ROS and RNS production, subcellular localization, and signaling triggered by immunogenic danger signals.

Plants continuously monitor the environment to detect changing conditions and to properly respond, avoiding deleterious effects on their fitness and survival. An enormous number of cell surface and intracellular immune receptors are deployed to perceive danger signals associated with microbial infections. Ligand binding by cognate receptors represents the first essential event in triggering plant immunity and determining the outcome of the tissue invasion attempt. Reactive oxygen and nitrogen species (ROS/RNS) are secondary messengers rapidly produced in different subcellular localizations upon the perception of immunogenic signals. Danger signal transduction inside the plant cells involves cytoskeletal rearrangements as well as several organelles and interactions between them to activate key immune signaling modules. Such immune processes depend on ROS and RNS accumulation, highlighting their role as key regulators in the execution of the immune cellular program. In fact, ROS and RNS are synergic and interdependent intracellular signals required for decoding danger signals and for the modulation of defense-related responses. Here we summarize current knowledge on ROS/RNS production, compartmentalization, and signaling in plant cells that have perceived immunogenic danger signals.

Investigating the relationship between self-reported interoceptive experience and risk propensity

ABSTRACT Risky behaviour may be associated with visceral experiences, such as increased heart rate. Previous studies examining the relationship between perception of such signals (interoception) and risk-taking typically used behavioural tasks with potential for monetary reward. This approach may be less informative for understanding general risk propensity. In addition, such research does not usually consider the varied ways individuals engage with interoceptive signals. However, examining these different forms of engagement may help us understand how subjective experience of interoception influences risk-taking. As such, we performed two surveys (n = 471, primarily young adults) to examine the relationship between self-reported engagement with interoceptive signals (measured using the Multidimensional Assessment of Interoceptive Awareness) and a generalised measure of risk propensity (the General Risk Propensity Scale). Results indicated that different ways of interpreting or engaging with interoceptive signals were differentially associated with risk propensity. In particular, they provide preliminary evidence that those with the ability to ignore or not worry about visceral signals when they are uncomfortable display greater risk propensity (and these effects may possibly be gender-specific).

Hidden shifts in allometry scaling between sound production and perception in anurans.

Animal communication consists of signal production and perception, which are crucial for social interactions. The main form used by anurans is auditory communication, in most cases produced as advertisement calls. Furthermore, sound perception happens mainly through an external tympanic membrane, and plays an important role in social behavior. In this study, we evaluated the influence of body and tympanic membrane sizes on call frequency across the phylogeny of anurans. We use data on snout-vent length, tympanic membrane diameter, and dominant frequency of the advertisement call from the literature and from natural history museum collections. We mapped these traits across the anuran phylogeny and tested different models of diversification. Our final dataset includes data on body size, tympanic membrane size, and call dominant frequency of 735 anuran species. The best explanatory model includes body and tympanum size with no interaction term. Although our results show that call frequency is strongly constrained by body and tympanum size, we identify five evolutionary shifts in allometry from that ancestral constraint. We relate these evolutionary shifts to the background noise experienced by populations. Body size is important for myriad ecological interactions and tympanum size is strongly associated with female call frequency preferences. Thus, allometric escape in frog calls might arise through environmental selection such as breeding in fast flowing or soundscape competition, as well as sexual selection linked to tympanum size.

Cartilage‐Inspired Multidirectional Strain Sensor with High Elasticity and Anisotropy Based on Segmented Embedded Strategy

AbstractFlexible, stretchable, and sensitive multidirectional sensing systems that can decouple different mechanical inputs and identify multidirectional signals are crucial for dynamic human signal perception and intelligent human–computer interaction. Most reported multidirectional sensors are suitable for discriminating in‐plane deformation directions, and the sensing materials are difficult to balance between stretchability and mechanical strength. Here, a segmented embedded structure strategy inspired by the interlaced structure of cartilage is proposed. This strategy combines soft and hard materials in a topological and zipper‐shear chain manner and balances the performance of reinforced composites with flexibility and high toughness. In the case of segmented embedded hydrogels (SEHs), a wearable multidirectional sensing system that can decouple and identify planar strain/pressure is constructed. The multidirectional sensing system exploits the inherent anisotropy and layered structure design of composites to decouple the sensing functions. Supported by machine learning algorithms, the high accuracy demonstration of the multidirectional sensors in typical multidirectional motion joint posture monitoring and recognition confirms their potential in practical applications such as personal health sensing and human–computer interaction.

Genome-wide identification of long non-coding RNAs and their potential functions in radish response to salt stress.

Long non-coding RNAs (lncRNAs) are increasingly recognized as cis- and trans-acting regulators of protein-coding genes in plants, particularly in response to abiotic stressors. Among these stressors, high soil salinity poses a significant challenge to crop productivity. Radish (Raphanus sativus L.) is a prominent root vegetable crop that exhibits moderate susceptibility to salt stress, particularly during the seedling stage. Nevertheless, the precise regulatory mechanisms through which lncRNAs contribute to salt response in radish remain largely unexplored. In this study, we performed genome-wide identification of lncRNAs using strand-specific RNA sequencing on radish fleshy root samples subjected to varying time points of salinity treatment. A total of 7,709 novel lncRNAs were identified, with 363 of them displaying significant differential expression in response to salt application. Furthermore, through target gene prediction, 5,006 cis- and 5,983 trans-target genes were obtained for the differentially expressed lncRNAs. The predicted target genes of these salt-responsive lncRNAs exhibited strong associations with various plant defense mechanisms, including signal perception and transduction, transcription regulation, ion homeostasis, osmoregulation, reactive oxygen species scavenging, photosynthesis, phytohormone regulation, and kinase activity. Notably, this study represents the first comprehensive genome-wide analysis of salt-responsive lncRNAs in radish, to the best of our knowledge. These findings provide a basis for future functional analysis of lncRNAs implicated in the defense response of radish against high salinity, which will aid in further understanding the regulatory mechanisms underlying radish response to salt stress.

ASF1 regulates asexual and sexual reproduction in Stemphylium eturmiunum by DJ-1 stimulation of the PI3K/AKT signaling pathway

Most fungi display a mixed mating system with both asexual and sexual reproduction. The timing of the two modes of reproduction must be carefully coordinated through signal perception and coordination in the cell along with chromatin modification. Here, we investigated coordination of reproductive output by investigating the function of the histone chaperone anti-silencing factor 1 (ASF1) in a fungal species amenable to characterization of both asexual and sexual reproduction. We used knockout approach to show that SeASF1 influenced asexual and sexual reproduction in Stemphylium eturmiunum. SeASF1-deleted strains failed to produce pseudothecia, but produce abnormal conidia and showed an irregular distribution of nuclei in mycelium. Transcriptome sequencing was then used to identify genes with altered expression in the SeASF1-deleted strains. The transcriptional expression of the identified SeDJ-1 was strongly regulated by SeASF1. The interaction of SeDJ-1 and SeASF1 was confirmed using Y2H, Co-IP, and pull-down. Due to some components of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway were known to interact with DJ-1 in mammals, we verified SePI3K, an element of PI3K/AKT signaling pathway in S. eturmiunum, was directly linked to SeDJ-1 and then these two proteins were defined as a coordinator of reproduction. However, knockout of SeDJ-1 or SePI3K altered the asexual and sexual reproduction, but SePI3K recovered the asexual and sexual development of ∆Sedj-1. The SeDJ-1-M6 segment of SeDJ-1 was essential for its interaction with SePI3K and played a critical role in restoring sexual reproduction in the ∆Sepi3k, providing a deep understanding of the regulatory mechanism of SeDJ-1 in S. eturmiunum development. Summarily, SeASF1 is able to trigger SeDJ-1 and SeDJ-1can also activate SePI3K, which is orchestrally involved in asexual and sexual reproduction in S. eturmiunum. All these results reveal that SeASF1 manipulates asexual and sexual reproduction in S. eturmiunum by SeDJ-1 perception of PI3K/AKT signaling pathway. These data highlight the deep similarities in coordinating asexual and sexual processes in both fungi and eukaryotes in general.

Seeing a Talking Face Matters: Gaze Behavior and the Auditory-Visual Speech Benefit in Adults' Cortical Tracking of Infant-directed Speech.

In face-to-face conversations, listeners gather visual speech information from a speaker's talking face that enhances their perception of the incoming auditory speech signal. This auditory-visual (AV) speech benefit is evident even in quiet environments but is stronger in situations that require greater listening effort such as when the speech signal itself deviates from listeners' expectations. One example is infant-directed speech (IDS) presented to adults. IDS has exaggerated acoustic properties that are easily discriminable from adult-directed speech (ADS). Although IDS is a speech register that adults typically use with infants, no previous neurophysiological study has directly examined whether adult listeners process IDS differently from ADS. To address this, the current study simultaneously recorded EEG and eye-tracking data from adult participants as they were presented with auditory-only (AO), visual-only, and AV recordings of IDS and ADS. Eye-tracking data were recorded because looking behavior to the speaker's eyes and mouth modulates the extent of AV speech benefit experienced. Analyses of cortical tracking accuracy revealed that cortical tracking of the speech envelope was significant in AO and AV modalities for IDS and ADS. However, the AV speech benefit [i.e., AV > (A + V)] was only present for IDS trials. Gaze behavior analyses indicated differences in looking behavior during IDS and ADS trials. Surprisingly, looking behavior to the speaker's eyes and mouth was not correlated with cortical tracking accuracy. Additional exploratory analyses indicated that attention to the whole display was negatively correlated with cortical tracking accuracy of AO and visual-only trials in IDS. Our results underscore the nuances involved in the relationship between neurophysiological AV speech benefit and looking behavior.

Broadband acoustic signal enhancement via gradient metamaterials coupled to crystals

In this work, a phononic crystal gradient metamaterial structure (PCGMs) is proposed based on the strong wave compression effect coupled with equivalent medium theory to achieve enhancement and directional sensing of weak target acoustic signals. Compared with the conventional gradient structure, PCGMs exhibit superior acoustic enhancement performance and wider range of acoustic response capability. Numerical analysis and experimental validation consistently demonstrate that PCGMs can effectively enhance the target frequency signals in harmonic signals. This study breaks through the detection limit of acoustic sensing systems and provides a great method for engineering applications of weak acoustic signal perception.