State Of Body Research Articles

Body image disturbance, interoceptive sensibility and the body schema across female adulthood: a pre-registered study

IntroductionBody image disturbance (BID) typically involves explicit negative attitudes toward one’s shape and weight and is associated with altered interoceptive sensibility (the subjective perception of internal bodily states). This association is a known risk factor for the development and maintenance of eating disorders. However, while research has centred on younger women with eating disorders, diverse facets of BID appear in women without eating disorders across adulthood. Research shows that in the general population, young women (ages 18–25) with high BID exhibit disturbances in the body schema: an implicit sensorimotor representation of the body in space which includes mental simulation of a movement such as motor imagery. Given that body image is subject to age-related influences, it is important to investigate how age-related variation in BID can influence the body schema beyond young adulthood alone. Here, we examine the relationship between BID, interoceptive sensibility and the body schema across female adulthood.MethodsCross-sectional data was collected online from 1,214 women across four age groups: Young adults (18–24), Adults (25–39), Middle-aged adults (40–59), and Older aged adults (60–75). BID was indexed by questionnaires measuring body objectification, state, and trait body dissatisfaction. Interoceptive sensibility (IS) was measured using the MAIA-2 questionnaire. The body schema was evaluated through the Own Body Transformation task: a mental rotation task which assesses the capacity to make an embodied mental transformation.ResultsAnalyses revealed that while body objectification and trait body dissatisfaction decreased from young to older adulthood, state body dissatisfaction showed a marked increase. A negative relationship between IS and BID across all age groups was also evidenced. Finally, age, BID and orientation of the presented body were significant predictors of the time taken to make an embodied transformation.DiscussionThese findings highlight the consistent relationship of BID and IS across age groups beyond young adulthood and demonstrate the varying importance of different aspects of BID as individuals age. We also evidence for the first time that disruptions in body image have the potential to impact implicit sensorimotor representations of the body even in women without eating disorders across female adulthood.

Relationship Between Pre-Pregnancy Body Mass Index (BMI), Number of Pregnancies, and Number of Nutrition Education Participation with Circumference Upper Arm (LILA) of Pregnant Women

Pregnant women's nutritional condition is determined by their Mid-Upper Arm Circumference (MUAC), which measures the body's state of balance. Factors influencing pregnant women's nutritional status include a history of body mass index before pregnancy, the number of pregnancies, and the number of participations in nutrition education. This study sought to discover the link between the history of body mass index before pregnancy, the number of pregnancies, and the number of participations in nutrition education with Mid- Upper Arm Circumference (MUAC) of pregnant women in the Working Area of the Tanjung Bintang Inpatient Public Health Center in 2022. The type of research is observational, analytic design, and cross-sectional, conducted from November to December 2022. The population in the study was 286, and the total sample was 80 respondents using the basic method of random sampling. The instrument used is a questionnaire. The data analysis used is the Spearman Correlation test. The results showed that the average Mid- Upper Arm Circumference (MUAC)of pregnant women was 25.54 with a standard deviation of 3.01, the average respondent's history of BMI was 22.272 kg/m2, the average number of respondents' pregnancies was 2.31 times, the average participation in nutrition education respondents as much as 2.93 times. The data analysis results showed a relationship between body mass index (p=0.0001) and the number of pregnancies (p=0.004) with the Mid- Upper Arm Circumference (MUAC)of pregnant women. There was no correlation between the number of participants in nutrition education (p=0.698) and the Mid- Upper Arm Circumference (MUAC)of pregnant women. It is hoped that the results of this study can add to knowledge about the relationship between the history of body mass index before pregnancy, the number of pregnancies, and the number of participants in nutrition education with MUAC for pregnant women.

The Psychosomatic Traits of “People with the Five Elements in Traditional Chinese Medicine”: A Qualitative Study

ObjectiveTo identify the representative attributes of the five elements of a person with a qualitative methodology and provide the basis for the clinical diagnosis and treatment of “people with the five elements in traditional Chinese medicine (TCM).” MethodsData collected from the literature review, two sessions of brainstorming of experts with related experience in “people with the five elements in TCM” from October 2020 to December 2020, and six rounds of in-depth interviews with 30 participants who had various attributes of the five elements from March 2021 to October 2021 were analyzed. Triangulation was used in this study, and theming and synthesizing were used to analyze the data. ResultsA total of 31 experts and 30 interviewees participated in this study. The median age of the experts and interviewees were 48.0 and 38.5 years, respectively; 51.66% and 54.8% of experts and interviewees, respectively, were men. The descriptors of facial diagrams of “people with the five elements in TCM” were complexion, shape, distribution state of facial bones, convergence trend of facial muscles, and facial expression. A theoretical model of “people with the five elements in TCM” was shaped based on these findings. ConclusionsThe study suggests a possibility for bridging the gap between personality and bodily state, identifying an avenue for personality research from the perspective of TCM.

The effect of 10-week long yoga training on interoceptive abilities: cross-sectional and longitudinal investigation of cardiac and gastric accuracy

Based on their characteristics, it is likely that mind–body techniques develop interoception, the perception of bodily state. Nevertheless, findings on mindfulness, meditation, yoga, and body scan techniques are inconclusive. Additionally, the methodological scope is not exhaustive, neither in terms of the intervention nor the applied measure of interoception. This study investigated for the first time the effect of regular yoga training on cardiac and gastric perceptual ability (measured with the mental heartbeat tracking task and the water load task, respectively). With the involvement of 90 female university students (yoga group n = 57, control group n = 33) we did not find any connection between baseline heartbeat perception score and gastric fullness. Moreover, the applied 10-week-long regular yoga training did not develop any of the measured interoceptive abilities. We conclude that yoga might develop other abilities than these specific sensations. Very probably, the measured cardiac and gastric perceptual abilities do not represent bodily sensations in general. It would be worth to investigate, however, the effect of longer yoga training on interoception.

Study and application of coupling relationship between water-salt-resistivity-soil structure in saline soils in arid and semi-arid areas of northwest China

Widespread saline soils in Northwest China pose a serious threat to the region's ability to use infrastructure safely because they are prone to soil structure damage when subjected to external environmental fluctuations, which in turn affects the stability of the foundations for buildings. The non-destructive approach of measuring resistivity can be used to swiftly reflect the subsoil body's state and make assumptions about its safety. However, the electrical resistivity of the underground soil body can be used to quickly identify unstable areas because the resistivity is influenced by the water content, salt content, and structural characteristics of the soil body. To do this, it is necessary to understand the coupling relationship between various factors. In this study, we first constructed samples with various water, salt, and soil structure characteristics, and then used indoor tests, such as soil resistivity measurement and thermogravimetric analysis, to analyze the multiple factors affecting the resistivity characteristics of the soil. The relationship between soil resistivity and actual saline soil diseases in Northwest China was then further discussed in conjunction with the results of the indoor tests and analyses. subsequently, the resistivity and soil properties have been measured in the field at specific locations in Northwest China where railway roadbeds are diseased. The study's findings can theoretically support a deeper comprehension of the law and mechanism of soil resistivity change, as well as provide assistance for building infrastructure in Northwest China.

Disrupted interoceptive awareness by auditory distractor: Difficulty inferring the internal bodily states?

Recent studies have associated interoceptive awareness, the perception of internal bodily sensations, with a predictive mechanism of perception across all sensory modalities. According to the framework, volitional attention plays a pivotal role in interoceptive awareness by prioritizing interoceptive sensations over exteroceptive ones. Consequently, it is hypothesized that the presence of irrelevant stimuli would disrupt the attentional modulation and interoceptive awareness, which remains untested. In this study, we investigated if interoceptive awareness is diminished by unrelated auditory distractors to validate the proposed perceptual framework. A total of 30 healthy human volunteers performed the heartbeat counting task both with and without auditory distractors. Additionally, we measured participant’s psychophysiological traits related to interoception, including the high-frequency component of heart rate variability (HF-HRV) and trait interoceptive sensibility. The results showed that interoceptive accuracy, confidence, and heartbeat intensity decreased in the presence of distractor sound. Moreover, individuals with higher HF-HRV and a greater tendency to worry about bodily states experienced a more pronounced distractor effect on interoceptive awareness. These results provide support for the perceptual mechanism of interoceptive awareness in terms of the predictive process, highlighting the impact of relative precision across interoceptive and exteroceptive signals on perceptual experiences.

The Design Principle of Allostatic Mechanisms: The Free Energy Principle

Homeostasis is maintained by neural reflex controls, which attempt to maintain the body's internal organs within a predetermined range. However, when deviations are significant, homeostasis may not be restored by these standard controls. Therefore, a function called allostasis is necessary to maximize the energy efficiency of bodily functions, anticipate changing needs (e.g., a future increase in body temperature or oxygen demand), and regulate the body's state before dyshomeostasis occurs. In terms of the free energy principle (FEP), the expectation to survive (i.e., to stay within established confines and to maintain homeostatic integrity over time) is realized by a hierarchical prediction mechanism. Allostasis requires the integration of exteroceptive, interoceptive, and proprioceptive signals. In this paper, the neural mechanism of allostasis is discussed in terms of the FEP.

Is That My Heartbeat? Measuring and Understanding Modality-Dependent Cardiac Interoception in Virtual Reality.

Measuring interoception ('perceiving internal bodily states') has diagnostic and wellbeing implications. Since heartbeats are distinct and frequent, various methods aim at measuring cardiac interoceptive accuracy (CIAcc). However, the role of exteroceptive modalities for representing heart rate (HR) across screen-based and Virtual Reality (VR) environments remains unclear. Using a PolarH10 HR monitor, we develop a modality-dependent cardiac recognition task that modifies displayed HR. In a mixed-factorial design (N=50), we investigate how task environment (Screen, VR), modality (Audio, Visual, Audio-Visual), and real-time HR modifications ( ±15%, ±30%, None) influence CIAcc, interoceptive awareness, mind-body measures, VR presence, and post-experience responses. Findings showed that participants confused their HR with underestimates up to 30%; environment did not affect CIAcc but influenced mind-related measures; modality did not influence CIAcc, however including audio increased interoceptive awareness; and VR presence inversely correlated with CIAcc. We contribute a lightweight and extensible cardiac interoception measurement method, and implications for biofeedback displays.

9 Interoceptive Attentiveness: Evidence for Neurofunctional Correlates from an EEG Source Localization Study

Objective:Since seminal work by Sherrington, the term interoception refers to the ability to sense modifications of internal bodily states as opposed to the ability to sense stimuli coming from outside the body itself. Despite conceptual changes regarding the afferent signals subserving this type of inner perception, the core of this definition is still valid and widely accepted. The critical contribution of internal state perception to self-regulation as well as higher-order cognitive processes has led to the development of psychometric and observational measures trying to capture individual interoceptive skills, focusing especially on the ability to orient attention to internal sensations. Nonetheless, despite growing interest in interoceptive attention (IAtt), little is known about neurofunctional correlates of our ability to redirect attention to internal sensations and consciously process them, as well as on potential objective biomarkers of IAtt performance.Participants and Methods:This study included 36 volunteers who were asked to complete a heart-beat counting task (HCT), a common IAtt task. During both resting-state and HCT, central electrophysiological (EEG, 32 electrodes) and cardiovascular activity (ECG, I lead) were recorded. eLORETA was used to estimate both task-related and resting-state intracortical sources of EEG signals. Statistical non-parametric mapping (SnPM) was used to draw and investigate contrast statistical maps between rest- and task-related cortical current density.Results:Contrast analyses comparing HCT and resting revealed higher Alpha frequency current density estimates during the task, with primary cortical seed in the right parahippocampal gyrus. Regression analyses of the relationship between IAtt scores and task-related changes in intracortical current density during HCT revealed a positive relationship for the Beta frequency bands with primary cortical seeds in the cingulate gyrus and insula. Conclusions:Findings add to available literature by further specifying the electrophysiological signature of interoceptive attentiveness, and suggest specific electrophysiological markers as objective measures of individual IAtt skills.

Integration of Interoception, Decision-Making, and Affect: Allostasis as Predictive Processing

Allostasis refers to the mechanism by which the brain changes bodily states to adapt to the environment in order to achieve stability or homeostasis. This concept was originally proposed by Sterling and Eyer in 1988. Recently, allostasis has been reconceptualized from the viewpoint of predictive processing, a theory arguing that the brain regulates perception and motor movement by generating predictions through inner models of the external world and self and minimizing the prediction error between the predictions and sensory signals. This idea provides integrated explanations of a wide range of phenomena, including homeostasis, decision-making, and the accompanying emotions and consciousness. Although this theory is a hypothesis, empirical evidence has been proposed in recent years. This article introduces the theory of predictive processing of allostasis, recent related research findings, and issues to be examined in the future.

Training the Moral Self: An 8-Week Mindfulness Meditation Program Leads to Reduced Dishonest Behavior and Increased Regulation of Interoceptive Awareness

ObjectivesRecent meta-analyses suggest that mindfulness meditation may enhance prosocial behavior, while evidence regarding moral behavior is still scarce. We combined a randomized controlled mindfulness training design with an ecologically valid moral decision-making task (Temptation to Lie Card Game; TLCG), in which participants were tempted to deceive an opponent to increase their monetary payoff.MethodTLCG and self-report measures (in the domains of attention regulation, body awareness, emotion regulation, and change in the perspective of the self) were administered to participants who underwent the mindfulness meditation training (experimental group, n = 44) or were waitlisted (control group, n = 25) twice: before and after the 8-week training.ResultsConcerning moral decision-making, we observed a significant effect involving condition, time, and group. Trained participants deceived significantly less in the post-training as compared with the pre-training phase (p = 0.03), while untrained ones showed no significant change (p = 0.58). In the self-reports, significant effects involving time and group were found for the Multidimensional Assessment of Interoceptive Awareness (MAIA-2) in Self-Regulation, Attention Regulation, Body Listening, and for the Five Facet Mindfulness Questionnaire (FFMQ) in Non-Reactivity to inner experience. Trained participants showed a time-related increase in all subscales scores, while untrained ones did not. Finally, a moderation analysis revealed a significant interaction between weekly mindfulness meditation training minutes and MAIA-2 Attention Regulation (post-training) on moral behavior change.ConclusionsOur preliminary results suggest that mindfulness meditation practice decreases self-serving dishonest behavior and increases awareness of one’s bodily and emotional state. In particular, the amount of mindfulness meditation practice predicted moral behavior change in practitioners who reported the highest regulation of attention towards internal bodily signals.PreregistrationThis study is not preregistered.

Effect of subconscious changes in bodily response on thought shifting in people with accurate interoception

Our thought states shift from one state to another from moment to moment. The relationship between the thought shifting and bodily responses is yet to be directly examined. This exploratory study examined the influence of cardiovascular reactivity and interoception—sensing an internal bodily state—on the shifting of thought states. Participants (N = 100, 70 women) completed two tasks: the heartbeat counting task (HCT) and the vigilance task (VT). We assessed their interoceptive accuracy through their performance on the HCT. The VT was a simple sustained attention task in which participants pressed a key when the target stimulus appeared and were asked to report their thoughts. We presented subliminal vibration stimuli to induce alterations in heart rate (i.e., vibration block). Results showed that participants with higher interoceptive accuracy reported more continuation of self-referential thought (about past episodes and future plans regarding themselves) during the vibration block than did those with lower interoceptive accuracy. These results suggest that individuals with higher interoceptive accuracy are more likely to be influenced by their subliminal bodily response, resulting in divergent attention from the task and intermittent self-referential thought.

Physical Education and Embodied Learning: A Review

Recent neuroscientific research highlighted interesting interactions between superior cognitive functions and the sensorimotor system. Overcoming the traditional views of the philosophy of mind and cognitive sciences, current empirical evidence shows that bodily states are the basis of information processing and that incarnation contributes to various aspects of mental phenomena. Starting from this theoretical framework, the purpose of this contribution is to outline, through exposure to the most significant discoveries in the world of neuroscience, the importance of Embodied Cognition as an emerging vision that considers the cognitive processes deeply rooted in the interaction of the body with the world. After careful selection and analysis of studies on neuroscience applied to teaching, the study focused on those who experienced in the school context embodied-teaching approaches aiming to promote transversal learning through movement and corporeality in action and interaction. The analysis highlights the strengths and critical points of the studies implemented in recent decades that focus on the integration and transversality of the body in learning. This is to understand whether embodied learning environments involving all spheres of personality can foster perception, knowledge, and conscious action in teaching and learning processes. An important result from the overview is the potential of theory in different educational environments and disciplines. The contemporary theoretical framework highlights the great potential of corporeality and physical education as actors in learning, but at the same time place in the foreground the need to experiment and disseminate new teaching approaches and perspectives.

Understanding Interoception and Its Importance in Body and Mind Functions: A Review

Interoception, the sensing of the body’s internal sensations, contributes to numerous aspects of human’s cognitive and affective abilities. Interoception mechanisms ensure physiological health through the coordination of homeostatic reflexes and allostatic responses. This review presents how deeply interoception controls our daily motivational behaviors and associated affective and emotional feelings. Since its discovery at the twilight of the 19th century, relentless research and experimental work have pushed far back the borders of interoception. Concept enrichment is still to find its limits: from its role in balancing and maintaining the energy-efficiency of the integrity and health of the body (homeostasis) to its emotional importance in learning, motivation and decision making, the field of interoception doesn't stop extending. Scientific measuring of interoceptive effects is also making fulgurant progress, though accuracy and relation between self-awareness and interoceptive attention are still to be fine-tuned. In addition, the review also addresses impairment caused by interoceptive deficiencies (alexithymia), commenting research and group experiments made in physical, emotional and physiological fields. Open questions are raised about whether interoception is a unitary function as well as about the ways to reduce individual weak interoceptive abilities, such as training and meditation. In conclusion, the signaling, sensing, and detection of bodily states are implicated in physical and mental well-being. Interoception research contributes to understanding into the dynamic interactions between body, brain, and mind.

Soreness Reminds Me of Grief: Patients With Chronic Pain Show Less Differentiated Representations of Emotional Feelings and Bodily States

People experience similarities between emotional feelings and bodily states on a daily basis, but both the magnitude and pervasiveness of this experiential similarity vary across individuals. Inspired by previous findings that chronic pain (CP) is characterized by strengthened pain-affect coupling and reduced interoceptive accuracy, we conducted 2 cross-sectional studies to examine whether patients with CP would exhibit less differentiated perception and mental representation of emotional feelings and bodily states. In study 1 (N = 500), patients with CP and healthy controls (HCs) completed a self-report questionnaire that asked explicitly about the perceived similarity between 5 basic emotion categories and a series of bodily states. In study 2 (N = 73), a specially designed false memory test was administered to examine whether patients with CP would have reduced differentiation of concepts of negative emotion and somatic distress. We found that patients with CP perceived greater and more pervasive similarities between emotional feelings and bodily states, as indicated by higher questionnaire scores and denser, less specialized bipartite emotion-body networks, both associated with lower subjective interoceptive accuracy. Furthermore, patients with CP formed false memories of negative emotion words (eg, grief) more readily than HCs after memorizing somatic distress words (eg, soreness), as if they represented negative emotion and somatic distress as a single, enmeshed semantic category. Our findings extend previous literature by demonstrating reduced discrimination between emotional and bodily experiences in CP that is not restricted to pain-related emotional and sensory experiences and may be related to a fundamentally less differentiated interoception. PerspectivesThis study shows that patients with chronic pain have a profoundly less differentiated perception and implicit conceptualization of emotional feelings and bodily states, which appears to be associated with altered interoception. These findings may provide new perspectives on why they often experience a stronger pain-affect coupling.

Psychophysiology of Monotonous Driving, Fatigue and Sleepiness in Train and Non-Professional Drivers: Driver Safety Implications.

Fatigue and sleepiness are complex bodily states associated with monotony as well as physical and cognitive impairment, accidents, injury, and illness. Moreover, these states are often characteristic of professional driving. However, most existing work has focused on motor vehicle drivers, and research examining train drivers remains limited. As such, the present study psychophysiologically examined monotonous driving, fatigue, and sleepiness in a group of passenger train drivers and a group of non-professional drivers. Sixty-three train drivers and thirty non-professional drivers participated in the present study, which captured 32-lead electroencephalogram (EEG) data during a monotonous driving task. Fatigue and sleepiness were self-evaluated using the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, the Karolinksa Sleepiness Scale, and the Checklist of Individual Strength. Unexpectedly, fatigue and sleepiness scores did not significantly differ between the groups; however, train drivers generally scored lower than non-professional drivers, which may be indicative of individual and/or industry attempts to reduce fatigue. Across both groups, fatigue and sleepiness scores were negatively correlated with theta, alpha, and beta EEG variables clustered towards the fronto-central and temporal regions. Broadly, these associations may reflect a monotony-associated blunting of neural activity that is associated with a self-reported fatigue state.

Restrictions in a distributed complex fractional order linear constitutive equations of viscoelasticity

We analyze a viscoelastic body in a linear stress state by the use of the distributed complex order fractional derivative in the constitutive equation. A model is formulated so that it takes into account all complex order derivatives of the form t0Dtα+iβ(α), α∈[α1,α2]⊂(0,1), β∈C1([α1,α2]). Using a new procedure, we derive restrictions on a model that follows from the Clausius–Duhem inequality under isothermal conditions. We apply our analysis to the creep test, as well as to generalized wave equation on R, with a specific constitutive equation of Kelvin–Voigt type.

Continuous peripersonal tracking accuracy is limited by the speed and phase of locomotion

Recent evidence suggests that perceptual and cognitive functions are codetermined by rhythmic bodily states. Prior investigations have focused on the cardiac and respiratory rhythms, both of which are also known to synchronise with locomotion—arguably our most common and natural of voluntary behaviours. Compared to the cardiorespiratory rhythms, walking is easier to voluntarily control, enabling a test of how natural and voluntary rhythmic action may affect sensory function. Here we show that the speed and phase of human locomotion constrains sensorimotor performance. We used a continuous visuo-motor tracking task in a wireless, body-tracking virtual environment, and found that the accuracy and reaction time of continuous reaching movements were decreased at slower walking speeds, and rhythmically modulated according to the phases of the step-cycle. Decreased accuracy when walking at slow speeds suggests an advantage for interlimb coordination at normal walking speeds, in contrast to previous research on dual-task walking and reach-to-grasp movements. Phasic modulations of reach precision within the step-cycle also suggest that the upper limbs are affected by the ballistic demands of motor-preparation during natural locomotion. Together these results show that the natural phases of human locomotion impose constraints on sensorimotor function and demonstrate the value of examining dynamic and natural behaviour in contrast to the traditional and static methods of psychological science.

Trait anxiety modulates the detection sensitivity of negative affect in speech: an online pilot study.

Acoustic perception of emotions in speech is relevant for humans to navigate the social environment optimally. While sensory perception is known to be influenced by ambient noise, and bodily internal states (e.g., emotional arousal and anxiety), their relationship to human auditory perception is relatively less understood. In a supervised, online pilot experiment sans the artificially controlled laboratory environment, we asked if the detection sensitivity of emotions conveyed by human speech-in-noise (acoustic signals) varies between individuals with relatively lower and higher levels of subclinical trait-anxiety, respectively. In a task, participants (n = 28) accurately discriminated the target emotion conveyed by the temporally unpredictable acoustic signals (signal to noise ratio = 10 dB), which were manipulated at four levels (Happy, Neutral, Fear, and Disgust). We calculated the empirical area under the curve (a measure of acoustic signal detection sensitivity) based on signal detection theory to answer our questions. A subset of individuals with High trait-anxiety relative to Low in the above sample showed significantly lower detection sensitivities to acoustic signals of negative emotions - Disgust and Fear and significantly lower detection sensitivities to acoustic signals when averaged across all emotions. The results from this pilot study with a small but statistically relevant sample size suggest that trait-anxiety levels influence the overall acoustic detection of speech-in-noise, especially those conveying threatening/negative affect. The findings are relevant for future research on acoustic perception anomalies underlying affective traits and disorders.

The relationship of affective and bodily states with goals and plans to increase physical activity: An 8-day study in students.

Planning is an important tool to translate intentions into physical activity (PA) behavior. Affective and bodily states are known to influence how much PA individuals perform, but their impact on to formulation of PA plans is not yet known. The aim of the current study is to explore the effect of within- and between-subject variations in affective and bodily states on the content of PA goals and plans. Over eight consecutive days, 362 students created action and coping plans to achieve their daily PA goals. They also reported their affective and bodily states. Generalized linear mixed effect models were used to analyze the associations between these states and the content of the goals and plans. The results showed that both between- and within-subject variations in affective and bodily states were associated with goals formulated in terms of minutes, the intensity and context of planned activities, and anticipated barriers, though more effects were found for within-subject differences. Affective and bodily states impact daily PA goals and plans, highlighting the dynamic nature of planning. Our findings can be a first step toward personalized suggestions for goals, action plans, and coping strategies that are based on individual affective and bodily states.