Intramolecular charge transfer and the function of vibronic excitons in photosynthetic light harvesting

A widely discussed explanation for the prevalence of pairs or clusters of closely spaced electronic chromophores in photosynthetic light-harvesting proteins is the presence of ultrafast and highly directional excitation energy transfer pathways mediated by vibronic excitons, the delocalized optical excitations derived from mixing of the electronic and vibrational states of the chromophores. We discuss herein the hypothesis that internal conversion processes between exciton states on the <100 fs timescale are possible when the excitonic potential energy surfaces are controlled by the vibrational modes that induce charge transfer character in a strongly coupled system of chromophores. We discuss two examples, the peridinin-chlorophyll protein from marine dinoflagellates and the intact phycobilisome from cyanobacteria, in which the intramolecular charge-transfer (ICT) character arising from out-of-plane distortion of the conjugation of carotenoid or bilin chromophores also results in localization of the initially delocalized optical excitation on the vibrational timescale. Tuning of the ground state conformations of the chromophores to manipulate their ICT character provides a natural photoregulatory mechanism, which would control the overall quantum yield of excitation energy transfer by turning on and off the delocalized character of the optical excitations.

Integrating attachment and linguistic perspectives on the coherence of narratives regarding close relationships: A qualitative illustration

In this multidisciplinary study, we offer an integrative view on the coherence of narratives regarding close relationships. We show how coherence, as conceptualized by attachment researchers, is manifested in discursive syntactic structure, as conceptualized by linguists. To illustrate this correspondence, we use narratives of six mothers about their adolescent child and their relationship. Narratives were elicited with the widely used Five Minute Speech Sample (FMSS) procedure and were coded according to the FMSS-coherence manual, tapping their clarity, consistency, and multidimensionality. In addition, the syntactic constructions employed by mothers were analyzed. FMSS were segmented into Clause Packages (CPs). Within CPs, overt syntactic markers, such as 'because,' as well as unmarked thematic and pragmatic relations, such as new vs. given information, were categorized as reflecting different levels of integration between clauses. As we demonstrate, mothers whose narratives were rated as more coherent employed more integrated CPs. We conclude by discussing the multi-layered nature of coherence. We consider how a multidisciplinary approach to coherence can enrich the understanding of personal narratives and open a new direction for research of close relationships as well as inform functional analyses of the linguistic expression of coherence.

Analysis of reading-task-based brain connectivity in dyslexic children using EEG signals

Developmental dyslexia, a neurodevelopment reading disorder, can impact even children with average intelligence. The present study examined the brain connectivity in dyslexic and control children during the reading task using graph theory. 19-channel electroencephalogram (EEG) signals were recorded from 15 dyslexic children and 15 control children. Functional connectivity was estimated by measuring the EEG coherence at 19 electrode locations, and graph measures were calculated using the graph theory method. Reading task results identified deprived task performance in dyslexic children against controls. Graph measures revealed longer path length, reduced clustering coefficient and reduced network efficiencies (in theta and alpha bands) of dyslexic group. At the nodal level, we found a significant increase in delta strength (T4 and T5 electrode locations) and reduced strength in theta (T6, P4, Fp1, F8 and F3) and alpha bands (T4, T3, P4 and F3) during the reading task in dyslexic group. In conclusion, the present study identified distinct graph measures between groups when performing a reading task and showed possible evidence for compromised brain networks in dyslexic group.

The contribution of EEG to assess and treat motor disorders in multiple sclerosis

OBJECTIVE

Electroencephalography (EEG) can highlight significant changes in spontaneous electrical activity of the brain produced by altered brain network connectivity linked to inflammatory demyelinating lesions and neuronal loss occurring in multiple sclerosis (MS). In this review, we describe the main EEG findings reported in the literature to characterize motor network alteration in term of local activity or functional connectivity changes in patients with MS (pwMS).

METHODS

A comprehensive literature search was conducted to include articles with quantitative analyses of resting-state EEG recordings (spectrograms or advanced methods for assessing spatial and temporal dynamics, such as coherence, theory of graphs, recurrent quantification, microstates) or dynamic EEG recordings during a motor task, with or without connectivity analyses.

RESULTS

In this systematic review, we identified 26 original articles using EEG in the evaluation of MS-related motor disorders. Various resting or dynamic EEG parameters could serve as diagnostic biomarkers of motor control impairment to differentiate pwMS from healthy subjects or be related to a specific clinical condition (fatigue) or neuroradiological aspects (lesion load).

CONCLUSIONS

We highlight some key EEG patterns in pwMS at rest and during movement, both suggesting an alteration or disruption of brain connectivity, more specifically involving sensorimotor networks.

SIGNIFICANCE

Some of these EEG biomarkers of motor disturbance could be used to design future therapeutic strategies in MS based on neuromodulation approaches, or to predict the effects of motor training and rehabilitation in pwMS.

Arousal coherence, uncertainty, and well-being: an active inference account

Here we build on recent findings which show that greater alignment between our subjective experiences (how we feel) and physiological states (measurable changes in our body) plays a pivotal role in the overall psychological well-being. Specifically, we propose that the alignment or 'coherence' between affective arousal (e.g. how excited we 'feel') and autonomic arousal (e.g. heart rate or pupil dilation) may be key for maintaining up-to-date uncertainty representations in dynamic environments. Drawing on recent advances in interoceptive and affective inference, we also propose that arousal coherence reflects interoceptive integration, facilitates adaptive belief updating, and impacts our capacity to adapt to changes in uncertainty, with downstream consequences to well-being. We also highlight the role of meta-awareness of arousal, a third level of inference, which may permit conscious awareness, learning about, and intentional regulation of lower-order sources of arousal. Practices emphasizing meta-awareness of arousal (like meditation) may therefore elicit some of their known benefits via improved arousal coherence. We suggest that arousal coherence is also likely to be associated with markers of adaptive functioning (like emotional awareness and self-regulatory capacities) and discuss mind-body practices that may increase coherence.

Physiological effects of dual target DBS in an individual with Parkinson's disease and a sensing-enabled pulse generator

INTRODUCTION

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidus (GP) is an established therapy for Parkinson's disease (PD). Novel DBS devices can record local field potential (LFP) physiomarkers from the STN or GP. While beta (13-30 Hz) and gamma (40-90 Hz) STN and GP LFP oscillations correlate with PD motor severity and with therapeutic effects of treatments, STN-GP interactions in electrophysiology in patients with PD are not well characterized.

METHODS

Simultaneous bilateral STN and GP LFPs were recorded in a patient with PD who received bilateral STN-DBS and GP-DBS. Power spectra in each target and STN-GP coherence were assessed in various ON- and OFF-levodopa and DBS states, both at rest and with voluntary movement.

RESULTS

OFF-levodopa and OFF-DBS, beta peaks were present at bilateral STN and GP, coincident with prominent STN-GP beta coherence. Levodopa and dual-target-DBS (simultaneous STN-DBS and GP-DBS) completely suppressed STN-GP coherence. Finely-tuned gamma (FTG) activity at half the stimulation frequency (62.5 Hz) was seen in the STN during GP-DBS at rest. To assess the effects of movement on FTG activity, we recorded LFPs during instructed movement. We observed FTG activity in bilateral GP and bilateral STN during contralateral body movements while on GP-DBS and ON-levodopa. No FTG was seen with STN-DBS or dual-target-DBS.

CONCLUSION

Dual-target-DBS and levodopa suppressed STN-GP coherence. FTG throughout the basal ganglia was induced by GP-DBS in the presence of levodopa and movement. This bilateral STN-FTG and GP-FTG corresponded with the least severe bradykinesia state, suggesting a pro-kinetic role for FTG.

Analyses of relational coherence and rule following: Consistent liars are preferred over occasional truth tellers

The current study explored the influence of different levels of speaker coherence on rule following and speaker preference. In Experiment 1, rules provided by three different speakers were either 100% accurate, 0% accurate, or 50% accurate/inaccurate. Experiment 2 was similar to Experiment 1 except that the speaker's coherence was adjusted to 80% accurate, 20% accurate, and 50% accurate/inaccurate, respectively. Overall, participants tended to follow coherent speaker rules and avoid following incoherent speaker rules during training and testing phases. The results also indicated that following and not following rules provided by speakers may be generalizable to novel stimuli and maintained in the absence of differential reinforcement (i.e., in experimental test phases). Additionally, in a preference test, participants tended to prefer coherent over incoherent and partially coherent speakers. Furthermore, participants tended to prefer the relatively more incoherent speaker (i.e., 0% or 20% accurate) over the 50% accurate coherent speaker in both experiments. Finally, a comparison of the results of both experiments indicated that different levels of relational coherence affected the variability of rule-following and speaker preference behaviors. These findings are discussed in the context of the complexities that appear to be involved in rule-following behaviors and speaker preference.

Coherence of Parental Representations Following Therapy for Autistic Children

Autistic children experience high rates of mental health challenges, and links have been found between child mental health and the parent-child relationship. As parents of autistic children are often actively involved in their child's treatment, it is important to consider aspects of the parent-child relationship within this context. The present study investigated changes in a component of the parent-child relationship, the coherence of parental representations, following participation in a 10-week cognitive behavioural therapy intervention designed to address autistic children's mental health challenges. Relationships were examined between coherence and child characteristics (i.e., autism symptoms, mental health), and associations with child treatment outcomes (i.e., mental health). Participants included 81 children (89% boys) aged 8 to 13 years and their parents (85% mothers) aged 35 to 54 years. Baseline levels of coherence were related to children's mental health symptoms but not autism symptoms. Although there were no significant changes in overall coherence across therapy, subscale-level improvements (i.e., concern, acceptance) emerged. Changes in coherence across therapy were linked with children's post-intervention behavioural symptoms and were approaching significance for internalizing problems, but were not associated with externalizing problems. It is critical to investigate factors that shape the coherence of parents' representations of their children, as this may provide insight into potential targets for intervention. Ascertaining whether participation in therapy improves parental coherence, and consequently child treatment outcomes, can advocate for parent-involved therapy, which will ultimately benefit the well-being of autistic children.

Development of a complex Interdisciplinary Nurse-coordinated SELf-MAnagement (INSELMA) intervention for patients with inflammatory arthritis

BACKGROUND

Apart from a consistent focus on treating inflammation, patients with inflammatory arthritis (IA) report a range of unmet needs. Many experience not only residual symptoms but also various other physical, psychological, and social effects. Therefore, this study aimed to develop a complex Interdisciplinary Nurse-coordinated self-management (INSELMA) intervention for patients with IA, as an add-on treatment to usual outpatient care for those with substantial disease impact.

METHODS

This study followed the British Medical Research Council's updated framework for developing complex interventions. The process encompassed the following steps: (1) The evidence base was identified; (2) workshops were held, involving 38 relevant stakeholders (managers, physicians, nurses, physiotherapists, occupational therapists, social workers, psychologists from hospitals and municipalities, and two patient research partners), to discuss and further develop the preliminary ideas; (3) relevant theories were identified (i.e., self-efficacy, acceptance and commitment therapy, and health literacy); (4) the intervention was modeled and remodeled and (5) the results, describing the final INSELMA intervention and outcomes.

RESULTS

The INSELMA intervention encompasses an initial biopsychosocial assessment, which is performed by a rheumatology nurse. Then, activities that the participant wishes to improve are identified and goals are set. The nurse refers the participant to a multidisciplinary team and coordinates their support and relevant services in the participant's municipality. In addition, the health professionals have the opportunity to hold two interdisciplinary conferences during the intervention period. The participant and the health professionals work to achieve the set goals during a 6-month period, which ends with a status assessment and a discussion of further needs. The INSELMA intervention aims to increase self-management, reduce the impact of IA (e.g., pain, fatigue, sleep problems, and absenteeism), and increase self-efficacy, quality of life, mental well-being, work ability, and physical activity.

CONCLUSIONS

The development of the INSELMA intervention involved stakeholders from two Danish rheumatology outpatient clinics, patient research partners and municipalities. We believe that we have identified important mechanisms to increase the self-management and quality of life of people with IA and to decrease the disease impact in those who are substantially affected. The health professionals involved have developed competences in delivering the intervention and it is ready to be tested in a feasibility study.

Topic models with elements of neural networks: investigation of stability, coherence, and determining the optimal number of topics

Topic modeling is a widely used instrument for the analysis of large text collections. In the last few years, neural topic models and models with word embeddings have been proposed to increase the quality of topic solutions. However, these models were not extensively tested in terms of stability and interpretability. Moreover, the question of selecting the number of topics (a model parameter) remains a challenging task. We aim to partially fill this gap by testing four well-known and available to a wide range of users topic models such as the embedded topic model (ETM), Gaussian Softmax distribution model (GSM), Wasserstein autoencoders with Dirichlet prior (W-LDA), and Wasserstein autoencoders with Gaussian Mixture prior (WTM-GMM). We demonstrate that W-LDA, WTM-GMM, and GSM possess poor stability that complicates their application in practice. ETM model with additionally trained embeddings demonstrates high coherence and rather good stability for large datasets, but the question of the number of topics remains unsolved for this model. We also propose a new topic model based on granulated sampling with word embeddings (GLDAW), demonstrating the highest stability and good coherence compared to other considered models. Moreover, the optimal number of topics in a dataset can be determined for this model.

Transitivity, coherence, and reliability of network meta-analyses comparing proximal humerus fracture treatments: a meta-epidemiological study

BACKGROUND

Network meta-analyses can be valuable for decision-makers in guiding clinical practice. However, for network meta-analysis results to be reliable, the assumptions of both transitivity and coherence must be met, and the methodology should adhere to current best practices. We aimed to assess whether network meta-analyses of randomized controlled trials (RCTs) comparing interventions for proximal humerus fractures provide reliable estimates of intervention effects.

METHODS

We searched PubMed, EMBASE, The Cochrane Library, and Web of Science for network meta-analyses comparing interventions for proximal humerus fractures. We critically assessed the methodology regarding the development of a protocol, search strategy, trial inclusion, outcome extraction, and the methods used to conduct the network meta-analyses. We assessed the transitivity and coherence of the network graphs for the Constant score (CS), Disabilities of the Arm, Shoulder, and Hand score (DASH), and additional surgery. Transitivity was assessed by comparing probable effect modifiers (age, gender, fracture morphology, and comorbidities) across intervention comparisons. Coherence was assessed using Separating Indirect from Direct Evidence (SIDE) (Separating Indirect from Direct Evidence) and the design-by-treatment interaction test. We used CINeMA (Confidence in Network Meta-analyses) to assess the confidence in the results.

RESULTS

None of the three included network meta-analyses had a publicly available protocol or data-analysis plan, and they all had methodological flaws that could threaten the validity of their results. Although we did not detect incoherence for most comparisons, the transitivity assumption was violated for CS, DASH, and additional surgery in all three network meta-analyses. Additionally, the confidence in the results was 'very low' primarily due to within-study bias, reporting bias, intransitivity, imprecision, and heterogeneity.

CONCLUSIONS

Current network meta-analyses of RCTs comparing interventions for proximal humerus fractures do not provide reliable estimates of intervention effects. We advise caution in using these network meta-analyses to guide clinical practice. To improve the utility of network meta-analyses to guide clinical practice, journal editors should require that network meta-analyses are done according to a predefined analysis plan in a publicly available protocol and that both coherence and transitivity have been adequately assessed and reported.

Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: An EEG study

INTRODUCTION

Despite its complexity, deciphering nodal interaction is imperative to understanding a neural network. Network interaction is an even more complicated topic that must be addressed. This study aimed to examine the relationship between the brain waves of two canonical brain structures, i.e., the frontoparietal and limbic compartments, during a resting state.

METHODS

Electroencephalography (EEG) of 51 subjects in eye-closed condition was analyzed, and the eLORETA method was applied to convert the signals from the scalp to the brain. By way of community detection, representative neural nodes and the associated mean activities were retrieved. Total and lagged coherences were computed to indicate functional connectivity between those neural nodes. Two global network properties were elucidated based on the connectivity measures, i.e., global efficiency and mean functional connectivity strength. The temporal correlation of the global network indices between the two studied networks was explored.

RESULTS

It was found that there was a significant trend of positive correlation across the four metrics (lagged vs. total coherence x global efficiency vs. average connectivity). In other words, when the neural interaction in the FP network was stronger, so did that in the limbic network, and vice versa. Notably, the above interaction was not spectrally specific and only existed at a finer temporal scale (under hundreds of milliseconds level).

CONCLUSION

The concordant change in network properties indicates an intricate balance between FP and LM compartments. Possible mechanisms and implications for the findings are discussed.

Muscle synergies are associated with intermuscular coherence and cortico-synergy coherence in an isometric upper limb task

To elucidate the underlying physiological mechanisms of muscle synergies, we investigated long-range functional connectivity by cortico-muscular (CMC), intermuscular (IMC) and cortico-synergy (CSC) coherence. Fourteen healthy participants executed an isometric upper limb task in synergy-tuned directions. Cortical activity was recorded using 32-channel electroencephalography (EEG) and muscle activity using 16-channel electromyography (EMG). Using non-negative matrix factorisation (NMF), we calculated muscle synergies from two different tasks. A preliminary multidirectional task was used to identify synergy-preferred directions (PDs). A subsequent coherence task, consisting of generating forces isometrically in the synergy PDs, was used to assess the functional connectivity properties of synergies. Overall, we were able to identify four different synergies from the multidirectional task. A significant alpha band IMC was consistently present in all extracted synergies. Moreover, IMC alpha band was higher between muscles with higher weights within a synergy. Interestingly, CSC alpha band was also significantly higher across muscles with higher weights within a synergy. In contrast, no significant CMC was found between the motor cortex area and synergy muscles. The presence of a shared input onto synergistic muscles within a synergy supports the idea of neurally derived muscle synergies that build human movement. Our findings suggest cortical modulation of some of the synergies and the consequential existence of shared input between muscles within cortically modulated synergies.

Towards a temporospatial framework for measurements of disorganization in speech using semantic vectors

Incoherent speech in schizophrenia has long been described as the mind making "leaps" of large distances between thoughts and ideas. Such a view seems intuitive, and for almost two decades, attempts to operationalize these conceptual "leaps" in spoken word meanings have used language-based embedding spaces. An embedding space represents meaning of words as numerical vectors where a greater proximity between word vectors represents more shared meaning. However, there are limitations with word vector-based operationalizations of coherence which can limit their appeal and utility in clinical practice. First, the use of esoteric word embeddings can be conceptually hard to grasp, and this is complicated by several different operationalizations of incoherent speech. This problem can be overcome by a better visualization of methods. Second, temporal information from the act of speaking has been largely neglected since models have been built using written text, yet speech is spoken in real time. This issue can be resolved by leveraging time stamped transcripts of speech. Third, contextual information - namely the situation of where something is spoken - has often only been inferred and never explicitly modeled. Addressing this situational issue opens up new possibilities for models with increased temporal resolution and contextual relevance. In this paper, direct visualizations of semantic distances are used to enable the inspection of examples of incoherent speech. Some common operationalizations of incoherence are illustrated, and suggestions are made for how temporal and spatial contextual information can be integrated in future implementations of measures of incoherence.

Timing of cognitive effects on afterdischarge termination

OBJECTIVE

We previously studied efficacy of cognitive tasks on afterdischarge termination in patients undergoing cortical stimulation and found that diffuse wavelet cross-coherence changes on electrocorticography were associated with termination efficacy. We now report wavelet cross-coherence findings during different time segments of trials during which afterdischarges ended.

METHODS

For 12 patients with implanted subdural electrodes, we compared wavelet cross-coherence findings among several 1-second portions of cognitive tasks, reflecting task presentation, patient replies, and afterdischarge termination.

RESULTS

Coherence decreased significantly and progressively over time for 16.89, 22.53, and 30.03 Hz frequency ranges, but increased with afterdischarge termination. Coherence first increased, and then decreased for the 7.13 Hz frequency range.

CONCLUSIONS

The findings suggest that cumulative but non-specific factors, likely related primarily to attention, influence the coherence results throughout the task, with a separate effect due to resolution of the afterdischarges at the end.

SIGNIFICANCE

Task performance is well known to localize to specific brain regions and to be restricted in timing. In contrast, attention and overall mental activation might be due to emergent properties of brain as a whole and that are less circumscribed in space or time. Cognitive tasks might modify seizures and other neurological disorders.

Spectral adjustment for spatial confounding

Adjusting for an unmeasured confounder is generally an intractable problem, but in the spatial setting it may be possible under certain conditions. We derive necessary conditions on the coherence between the exposure and the unmeasured confounder that ensure the effect of exposure is estimable. We specify our model and assumptions in the spectral domain to allow for different degrees of confounding at different spatial resolutions. One assumption that ensures identifiability is that confounding present at global scales dissipates at local scales. We show that this assumption in the spectral domain is equivalent to adjusting for global-scale confounding in the spatial domain by adding a spatially smoothed version of the exposure to the mean of the response variable. Within this general framework, we propose a sequence of confounder adjustment methods that range from parametric adjustments based on the Matérn coherence function to more robust semiparametric methods that use smoothing splines. These ideas are applied to areal and geostatistical data for both simulated and real datasets.

A recruitment through coherence theory of working memory

The interactions between prefrontal cortex and other areas during working memory have been studied for decades. Here we outline a conceptual framework describing interactions between these areas during working memory, and review evidence for key elements of this model. We specifically suggest that a top-down signal sent from prefrontal to sensory areas drives oscillations in these areas. Spike timing within sensory areas becomes locked to these working-memory-driven oscillations, and the phase of spiking conveys information about the representation available within these areas. Downstream areas receiving these phase-locked spikes from sensory areas can recover this information via a combination of coherent oscillations and gating of input efficacy based on the phase of their local oscillations. Although the conceptual framework is based on prefrontal interactions with sensory areas during working memory, we also discuss the broader implications of this framework for flexible communication between brain areas in general.

Effects of dynamic and isometric motor practice on position control, force control and corticomuscular coherence in preadolescent children

In this study, we investigated the effects of motor practice with an emphasis on either position or force control on motor performance, motor accuracy and variability in preadolescent children. Furthermore, we investigated corticomuscular coherence and potential changes following motor practice. We designed a setup allowing discrete wrist flexions of the non-dominant hand and tested motor accuracy and variability when the task was to generate specific movement endpoints (15-75 deg) or force levels (5-25% MVC). All participants were tested in both tasks at baseline and post motor practice without augmented feedback on performance. Following baseline assessment, participants (44 children aged 9-11 years) were randomly assigned to either position (PC) or force control (FC) motor practice or a resting control group (CON). The PC and FC groups performed four blocks of 40 trials motor practice with augmented feedback on performance. Following practice, improvements in movement accuracy were significantly greater in the PC group compared to the FC and CON groups (p < 0.001). None of the groups displayed changes in force task performance indicating no benefits of force control motor practice and low transfer between tasks (p-values:0.08-0.45). Corticomuscular coherence (C4-FCR) was demonstrated during the hold phase in both tasks with no difference between tasks. Corticomuscular coherence did not change from baseline to post practice in any group. Our findings demonstrate that preadolescent children improve position control following dynamic accuracy motor practice. Contrary to previous findings in adults, preadolescent children displayed smaller or no improvements in force control following isometric motor practice, low transfer between tasks and no changes in corticomuscular coherence.

Longitudinal Relations among Identity Distinctiveness, Continuity, and Integration among Dutch Adolescents

Identity distinctiveness, continuity, and coherence are all components of adolescents' identity development, but their longitudinal relations have rarely been examined. Data were analyzed on these three constructs collected over three years from 349 Dutch adolescents (M_age = 14.7, SD_age = 0.7, 215 [61.6%] girls and 133 [38.1%] boys). A cross-lagged panel model of the three constructs showed that stability was relatively high for distinctiveness and continuity, whereas coherence was less stable. Distinctiveness and continuity were correlated positively within time, but cross-lagged associations were mostly not significant: Only distinctiveness and coherence negatively predicted each other across waves. Results suggest that distinctiveness, continuity, and coherence may be interrelated, but may not drive the development of each other.

The QBIT Theory of Consciousness: Information, Correlation, and Coherence

The ultimate goal of the QBIT theory is to provide a scientific solution to the problem of consciousness. The theory assumes that qualia (plural for quale) are real physical entities. Each quale is a physical system consisting of qubits bonded together by quantum entanglement. The qubits of a quale are so intimately bonded together that they collectively form a unified whole that is more than (and different from) the sum of its parts. A quale is a highly organized, coherent system. Organization and coherence are manifestations of information. The more the amount of information in a system, the more organized, integrated, and coherent the system is. That is why the QBIT theory suggests that qualia are maximally entangled, maximally coherent systems containing high amounts of information, and extremely low amounts of entropy or uncertainty.

EEG Connectivity in ADHD Compared to a Normative Database: A Cohort Analysis of 120 Subjects from the ICAN Study

This study explores how EEG connectivity measures in children with ADHD ages 7-10 (n = 140) differ from an age-matched nonclinical database. We differentiated connectivity in networks, Brodmann area pairs, and frequencies. Subjects were in the International Collaborative ADHD Neurofeedback study, which explored neurofeedback for ADHD. Inclusion criteria were mainly rigorously diagnosed ADHD and a theta/beta power ratio (TBR) ≤ 4.5. Using statistical and machine learning algorithms, connectivity values were extracted in coherence, phase, and lag coherence at all Brodmann, subcortical, and cerebellar areas within the main networks in all EEG frequencies and then compared with a normative database. There is a higher rate of dysregulation (more than ± 1.97SD), in some cases as much as 75%, of the Brodmann pairs observed in coherence and phase between BAs 7, 10, and 11 with secondary connections from these areas to BAs 21, 30, 35, 37, 39, and 40 in the ADHD children as compared to the normative database. Left and right Brodmann areas 10 and 11 are highly disconnected to each other. The most dysregulated Brodmann Areas in ADHD are 7, 10, and 11, relevant to ADHD executive-function deficits and provide important considerations when developing interventions for ADHD children.

Diversification evidence of bitcoin and gold from wavelet analysis

To measure the diversification capability of Bitcoin, this study employs wavelet analysis to investigate the coherence of Bitcoin price with the equity markets of both the emerging and developed economies, considering the COVID-19 pandemic and the recent Russia-Ukraine war. The results based on the data from January 9, 2014 to May 31, 2022 reveal that compared with gold, Bitcoin consistently provides diversification opportunities with all six representative market indices examined, specifically under the normal market condition. In particular, for short-term horizons, Bitcoin shows favorably low correlation with each index for all years, whereas exception is observed for gold. In addition, diversification between Bitcoin and gold is demonstrated as well, mainly for short-term investments. However, the diversification benefit is conditional for both Bitcoin and gold under the recent pandemic and war crises. The findings remind investors and portfolio managers planning to incorporate Bitcoin into their portfolios as a diversification tool to be aware of the global geopolitical conditions and other uncertainty in considering their investment tools and durations.

Promoting climate actions: A cognitive-constraints approach

The present paper reports an experiment with a two-year-delayed (M = 695 days) follow-up that tests an approach to raising willingness to take political and personal climate actions. Many Americans still do not view climate change as a threat requiring urgent action. Moreover, among American conservatives, higher science literacy is paradoxically associated with higher anthropogenic climate-change skepticism. Our experimental materials were designed to harness the power of two central cognitive constraints - coherence and causal invariance, which map onto two narrative proclivities that anthropologists have identified as universal - to promote climate action across the political spectrum. Towards that goal, the essential role of these constraints in the causal-belief-formation process predicts that climate-change information would be more persuasive when it is embedded in a personal climate-action narrative, the evocation of which can benefit from exposure to parsimonious scientific explanations of indisputable everyday observations, juxtaposed with reasoners' own, typically less coherent explanations, occurring in a context that engages their moral stance. Our brief one-time intervention, conducted in ten U.S. states with the highest level of climate skepticism, showed that across the political spectrum, our materials raised appreciation of science, openness to alternative views, and willingness to take climate actions in the immediate assessment. It also raised how likely were reports two years later of having taken those actions or would have taken them had the opportunity existed, suggesting a long-lasting effect. Our approach adopts the framework that conceptions of reality are representations, and adaptive solutions in that infinite space of representations require cognitive constraints to narrow the search.

Specific patterns of coherence and phase lag index in particular regions as biomarkers of cognitive impairment in Parkinson's disease

INTRODUCTION

Cognitive impairment is a persistent and increasingly reported symptom of patients with Parkinson's disease (PD), significantly affecting daily functioning quality. This study aims to evaluate the functional connectivity of the brain network in patients with Parkinson's disease with various severities of cognitive decline using quantitative electroencephalography (EEG) analysis.

METHODS

Based on the EEG recorded in the resting state, the coherence and phase lag index were calculated to evaluate functional connectivity in 108 patients with Parkinson's disease divided into three groups according to their cognitive condition: dementia due to PD (PD-D), PD and mild cognitive impairment (PD-MCI) and cognitively normal patients (PD-CogN).

RESULTS

It was found that there were significantly different coherence values in the PD-D group compared to PD-CogN in different frequency bands. In most cases, there was a decrease in coherence in PD-D compared to PD-CogN. The most specific changes were revealed in the theta frequency band in the temporal right-frontal left and temporal right-frontal right regions. In the alpha frequency band, the most significant decreases were shown in the occipital right-frontal left and occipital left-frontal right areas. There were also statistically significant differences in phase lag index between many areas, especially in the theta frequency range.

CONCLUSIONS

These findings indicate that the functional connectivity patterns of coherence and phase lag index - found in a particular frequency band and region - could become a reliable biomarker for identifying cognitive impairment and differentiating its severity in PD patients.

Altered electroencephalography resting state network coherence in remitted MDD

Individuals with remitted depression are at greater risk for subsequent depression and therefore may provide a unique opportunity to understand the neurophysiological correlates underlying the risk of depression. Research has identified abnormal resting-state electroencephalography (EEG) power metrics and functional connectivity patterns associated with major depression, however little is known about these neural signatures in individuals with remitted depression. We investigate the spectral dynamics of 64-channel EEG surface power and source-estimated network connectivity during resting states in 37 individuals with depression, 56 with remitted depression, and 49 healthy adults that did not differ on age, education, and cognitive ability across theta, alpha, and beta frequencies. Average reference spectral EEG surface power analyses identified greater left and midfrontal theta in remitted depression compared to healthy adults. Using Network Based Statistics, we also demonstrate within and between network alterations in LORETA transformed EEG source-space coherence across the default mode, fronto-parietal, and salience networks where individuals with remitted depression exhibited enhanced coherence compared to those with depression, and healthy adults. This work builds upon our currently limited understanding of resting EEG connectivity in depression, and helps bridge the gap between aberrant EEG power and brain network connectivity dynamics in this disorder. Further, our unique examination of remitted depression relative to both healthy and depressed adults may be key to identifying brain-based biomarkers for those at high risk for future, or subsequent depression.

Oscillations in the dentate gyrus as a tool for the performance of the hippocampal functions: Healthy and epileptic brain

The dentate gyrus (DG) is part of the hippocampal formation and is essential for important cognitive processes such as navigation and memory. The oscillatory activity of the DG network is believed to play a critical role in cognition. DG circuits generate theta, beta, and gamma rhythms, which participate in the specific information processing performed by DG neurons. In the temporal lobe epilepsy (TLE), cognitive abilities are impaired, which may be due to drastic alterations in the DG structure and network activity during epileptogenesis. The theta rhythm and theta coherence are especially vulnerable in dentate circuits; disturbances in DG theta oscillations and their coherence may be responsible for general cognitive impairments observed during epileptogenesis. Some researchers suggested that the vulnerability of DG mossy cells is a key factor in the genesis of TLE, but others did not support this hypothesis. The aim of the review is not only to present the current state of the art in this field of research but to help pave the way for future investigations by highlighting the gaps in our knowledge to completely appreciate the role of DG rhythms in brain functions. Disturbances in oscillatory activity of the DG during TLE development may be a diagnostic marker in the treatment of this disease.

EEG coherences of the fronto-limbic circuit between patients with major depressive disorder and healthy controls

BACKGROUND

Imaging studies found that patients with major depressive disorder (MDD) showed abnormal functional connectivity in the fronto-limbic circuit, including the prefrontal cortex (PFC), anterior cingulate cortex (ACC), and limbic system (amygdala). This study used electroencephalography (EEG) coherence as an indicator of functional connectivity in the fronto-limbic circuit and examined the group differences between the MDD group and healthy controls (HC group), and the associations between EEG coherence and depressive symptoms.

METHODS

125 and 132 participants in the MDD and HC groups have measured the symptoms of depression and anxiety, and delta, theta, alpha, and beta1-beta4 EEG coherences in the fronto-limbic circuit and examined the differences between the two groups, and the associations between the EEG coherence and depressive symptoms were examined.

RESULTS

Lower theta, alpha, beta1, beta3, and beta4 coherence in the fronto-limbic circuit and higher beta2 coherence between the PFC and limbic system in the MDD group than in the HC group. Negative correlations between delta, theta, beta1, beta3, and beta4 coherence and total depression, cognitive depression, and somatic depression; positive correlations between beta2 coherences in the PFC and limbic system, and total depression and cognitive depression scores in the MDD group.

LIMITATIONS

Whether low EEG coherence in the fronto-limbic circuit is applicable to other subtypes of MDD requires further study.

CONCLUSIONS

Low EEG coherences in the fronto-limbic circuit were related to depressive symptoms, and increased functional connectivity in the fronto-limbic circuit can be applied by neurofeedback in future studies.

Speech intelligibility changes the temporal evolution of neural speech tracking

Listening to speech with poor signal quality is challenging. Neural speech tracking of degraded speech has been used to advance the understanding of how brain processes and speech intelligibility are interrelated. However, the temporal dynamics of neural speech tracking and their relation to speech intelligibility are not clear. In the present MEG study, we exploited temporal response functions (TRFs), which has been used to describe the time course of speech tracking on a gradient from intelligible to unintelligible degraded speech. In addition, we used inter-related facets of neural speech tracking (e.g., speech envelope reconstruction, speech-brain coherence, and components of broadband coherence spectra) to endorse our findings in TRFs. Our TRF analysis yielded marked temporally differential effects of vocoding: ∼50-110 ms (M50TRF), ∼175-230 ms (M200TRF), and ∼315-380 ms (M350TRF). Reduction of intelligibility went along with large increases of early peak responses M50TRF, but strongly reduced responses in M200TRF. In the late responses M350TRF, the maximum response occurred for degraded speech that was still comprehensible then declined with reduced intelligibility. Furthermore, we related the TRF components to our other neural "tracking" measures and found that M50TRF and M200TRF play a differential role in the shifting center frequency of the broadband coherence spectra. Overall, our study highlights the importance of time-resolved computation of neural speech tracking and decomposition of coherence spectra and provides a better understanding of degraded speech processing.

Observation of respiration-entrained brain oscillations with scalp EEG

In animal models, oscillations of local field potentials are entrained by nasal respiration at the frequency of breathing cycle in olfactory brain regions, such as the olfactory bulb and piriform cortex, as well as in the other brain regions. Studies in humans also confirmed these respiration-entrained oscillations in several brain regions using intracranial electroencephalogram (EEG). Here we extend these findings by analyzing coherence between cortical activity and respiration using high-density scalp EEG in twenty-seven healthy human subjects. Results indicated the occurrence of significant coherence between scalp EEG and respiration signals, although the number and locations of electrodes showing significant coherence were different among subjects. These findings suggest that scalp EEG can detect respiration-entrained oscillations. It remained to be determined whether these oscillations are volume conducted from the olfactory brain regions or reflect the local cortical activity.

Bilingualism modulates neural efficiency at rest through alpha reactivity

The aim of the present study was to investigate how resting state EEG rhythms reflect attentional processes and bilingual experience. We compared alpha and beta rhythms for monolingual and bilingual young adults in eyes open and eyes closed conditions using EEG measures of frequency power, reactivity, and coherence. Power shows the amount of brain activity at a given frequency band; reactivity indexes the desynchronization of neuronal activity when individuals open their eyes at rest; and coherence indicates the brain regions that have correlated activity. The results showed that bilinguals had similar alpha power as monolinguals in both resting conditions but less alpha reactivity across the whole scalp. There was also more focused activation for bilinguals expressed as more coherence in posterior electrodes, particularly when eyes were opened to direct attention. For beta, there were no group differences in power or reactivity, but there was higher coherence for monolinguals than bilinguals, a pattern consistent with previous literature showing that beta frequency was related to language learning and native language proficiency. These results are in line with a neural efficiency theory and suggest that bilinguals have a more efficient brain for attentional mechanisms than monolinguals at rest.

Essential Tremor accentuates the pattern of tremor-band coherence between upper-limb muscles

Although Essential Tremor is one of the most common movement disorders, current treatment options are relatively limited. Peripheral tremor suppression methods have shown potential, but we do not currently know which muscles are most responsible for patients' tremor, making it difficult to optimize suppression methods. The purpose of this study was to quantify the relationships between the tremorogenic activity in muscles throughout the upper limb. Muscle activity was recorded from the 15 major superficial upper-limb muscles in 24 subjects with Essential Tremor while they held various postures or made upper-limb movements. We calculated the coherence in the tremor band (4-12 Hz) between the activity of all muscle pairs and the time-varying phase difference between sufficiently coherent muscle pairs. Overall, the observed pattern somewhat mirrored functional relationships: agonistic muscle pairs were most coherent and in phase, whereas antagonist and unrelated muscle pairs exhibited less coherence and were either consistently in phase, consistently antiphase, consistently out of phase (unrelated pairs only), or else inconsistent. Patients exhibited significantly more coherence than control subjects (p<0.001) in the vast majority of muscle pairs (95 out of 105). Furthermore, differences between patients and controls were most pronounced among agonists; thus, the coherence pattern existing in control subjects was accentuated in patients with ET. We conclude that tremor-band activity is broadly distributed among the muscles of the upper limb, challenging efforts to determine which muscles are most responsible for a patient's tremor.

Potential Misfortunes in 'Making Sense': A Cross-Sectional Study in People with Chronic Pain

Making sense of one's circumstances is normally regarded as helpful, including in the context of chronic pain. However, sense-making may be associated with adverse impacts in daily functioning. To better understand the functions of sense-making, the objective of the current study was to develop, validate, and preliminarily examine a measure of potentially helpful and unhelpful forms of sense-making behavior in people seeking treatment for chronic pain. This measure is called the Sense Making Questionnaire (SMQ). Research participants included 451 adults consecutively attending a specialty interdisciplinary treatment for chronic pain. Data for this study derived from a standard set of measures participants completed prior to treatment. Exploratory Factor Analysis (EFA) produced a 3-factor solution based on 15 items, including Avoidance of Incoherence, Overthinking, and Functional Coherence. The first 2 of these factors and the total achieved adequate internal consistency. Construct validity of the SMQ scores was supported by significant correlations with measures of pain acceptance, committed action, cognitive fusion, and intolerance of uncertainty. The SMQ total score correlated significantly with pain interference, r = .23, depression, r = .41, and work and social adjustment, r = .30, all P < .001. In multiple regression analyses the total score also significantly predicted depression after age, gender, education, pain duration, pain intensity, and pain acceptance were statistically controlled, and it accounted for an additional 8.0% in explained variance. It appears that there is a distinction between literal coherence and functional coherence. In some situations, it may benefit people with chronic pain to shift focus from efforts to make literal sense of pain and instead to keep the focus on taking effective action even if this does not appear at first to make sense. PERSPECTIVE: This study in people seeking treatment for chronic pain includes development of a measure of behavior patterns related to making sense in chronic pain. It shows that sometimes these behavior patterns can be ineffective, as they appear negatively associated with emotional, physical, and social functioning.

Brain Connectivity in Dystonia: Evidence from Magnetoencephalography

Magnetoencephalography (MEG) detects synchronized activity within a neuronal network by measuring the magnetic field changes generated by intracellular current flow. Using MEG data, we can quantify brain region networks with similar frequency, phase, or amplitude of activity and thereby identify patterns of functional connectivity seen with specific disorders or disease states. In this review, we examine and summarize MEG-based literature on functional networks in dystonias. Specifically, we inspect literature evaluating the pathogenesis of focal hand dystonia, cervical dystonia, embouchure dystonia, the effects of sensory tricks, treatment with botulinum toxin and deep brain stimulation, and rehabilitation approaches. This review additionally highlights how MEG has potential for application to clinical care of patients with dystonia.

Stories of change in nutrition: lessons from a new generation of studies from Africa, Asia and Europe

How does nutrition improve? We need to understand better what drives both positive and negative change in different contexts, and what more can be done to reduce malnutrition. Since 2015, the Stories of Change in Nutrition studies have analysed and documented experiences in many different African and Asian countries, to foster empirically-grounded experiential learning across contexts. This article provides an overview of findings from 14 studies undertaken in nine countries in South Asia, sub-Saharan Africa, and Europe between 2017 and 2021. The studies used a combination of methods, including regression-decomposition analyses of national datasets to assess determinants of nutritional change; policy process and food environment analyses; and community-level research assessing attitudes to change. This article takes a narrative synthesis approach to identify key themes across the studies, paying particular attention to multisectoral determinants, changes in the food environment, the role of structural factors (including longstanding social inequities), and changes in political commitment, cross-sectoral coherence and capacity. Given the inherent multisectoral nature of nutrition, many countries are experimenting with different models of ensuring coherence across sectors that are captured in this body of work. The relative immaturity of the policy sector in dealing with issues such as obesity and overweight, and associated influences in the wider food environment, adds a further challenge. To address these interrelated issues, policy must simultaneously tackle nutrition's upstream (social/economic/equity) and downstream (health and dietary) determinants. Studies synthesised here provide empirically-driven inspiration for action.

Is Functional Connectivity after a First Unprovoked Seizure Different Based on Subsequent Seizures and Future Diagnosis of Epilepsy?

Background and Purpose

There are no highly sensitive biomarkers for epilepsy to date. Recently, promising results regarding functional connectivity analysis have been obtained, which may improve epilepsy diagnosis even in the absence of visible abnormality in electroencephalography. We aimed to investigate the differences in functional connectivity after a first unprovoked seizure between patients diagnosed with epilepsy within 1 year due to subsequent seizures and those who were not.

Methods

We compared quantitative electroencephalography power spectra and functional connectivity between 12 patients who were diagnosed with epilepsy (two or more unprovoked seizures) within 1 year and 17 controls (those not diagnosed within 1 year) using iSyncBrain^® (iMediSync Inc., Suwon, Korea; https://isyncbrain.com/). In the source-level analysis, the current distribution across the brain was assessed using the standardized low-resolution brain electromagnetic tomography technique, to compare relative power values in 68 regions of interest and connectivity (the imaginary part of coherency) between regions of interest.

Results

In the epilepsy group, quantitative electroencephalography showed lower alpha2 band power in left frontal, central, superior temporal, and parietal regions and higher beta2 power in both frontal, central, temporal, occipital, and left parietal regions compared with the control group. Additionally, epilepsy patients had significantly lower connectivity in alpha2 and beta2 bands than the controls.

Conclusions

Patients experiencing their first unprovoked seizure presented different brain function according to whether they have subsequent seizures and future epilepsy. Our results propose the potential clinical ability to diagnose epilepsy after the first unprovoked seizure in the absence of interictal epileptiform discharges.

Following the Rhythm of the Heart: HeartMath Institute's Path to HRV Biofeedback

This paper outlines the early history and contributions our laboratory, along with our close advisors and collaborators, has made to the field of heart rate variability and heart rate variability coherence biofeedback. In addition to the many health and wellness benefits of HRV feedback for facilitating skill acquisition of self-regulation techniques for stress reduction and performance enhancement, its applications for increasing social coherence and physiological synchronization among groups is also discussed. Future research directions and applications are also suggested.

The construction of Chinese indicator system on public health field investigation and short-term study hub: experience and implications

Background

The increasing of exchange activities among public health institutes and experts globally calls for a standardized operation to construct public health field investigation and short-term study hub (Field Study Hub). This can funcion as a platform to share experience in public health development in an accurate and comprehensive manner that would benefit global practices. This research aims to establish a supportive indicator system to guide the construction work.

Methods

Delphi method including two rounds of surveys were conducted among 82 senior public health experts. A structured questionnaire was designed to collect the opinions of the experts on the necessity of setting and feasibility of measurement for proposed 5 dimensions of 49 indicators and 7 additionally proposed ones. Percentage and score were used to describe the assessments, χ² and t tests to compare differences, Kappa and Cronbach’s alpha values to assess intra-rater and inter-rater reliabilities. Significance level α was 0.05. Bonferroni adjustment was used in the comparison of experts’ judgment basis.

Results

The percentages of experts choosing “Very good” or “Good” for necessity and feasibility in rounds 1 and 2 were 73.1–97.6% (85.8% ± 7.5%), 64.6–93.9% (82.8% ± 6.7%), 73.8–100% (91.0% ± 6.2%) and 72.5–100% (89.2% ± 7.3%) respectively. The scores of necessity were higher than those of feasibility, and the differences in the dimensions of “Key experience”, “Capacity for logistic support” and the total were statistically significant (t₁₁ = 2.920, t₁₂ = 3.035, t₃₁ = 4.448, t₃₂ = 2.664, t_t1 = 3.794, t_t2 = 3.007, P < 0.05). The fourteen most necessary indicators were identified. The judgment bases of “Theory” and “Experience” were higher than “Knowledge” and “Intuition” statistically significantly (round 2: χ_TK² = 39.020, χ_EK² = 67.692, χ_TI² = 45.823, χ_EI² = 76.515, P < 0.0125). The Kappa values exceeded 40 with the maximum as 75 and the Cronbach’s alphas exceeded 0.8000 with the maximum as 0.9732.

Conclusions

A set of 5 dimensions of 56 indicators with good necessity and feasibility were developed to technically support and well evaluate the construction of field study hub in public health institutions. This was of high significance because it tended to provide a preliminary baseline for the standardized practice in global health. Also, the present research might serve as a methodological reference for the development of other indicator sets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41256-022-00273-z.

Short text topic modelling approaches in the context of big data: taxonomy, survey, and analysis

Social media platforms such as (Twitter, Facebook, and Weibo) are being increasingly embraced by individuals, groups, and organizations as a valuable source of information. This social media generated information comes in the form of tweets or posts, and normally characterized as short text, huge, sparse, and low density. Since many real-world applications need semantic interpretation of such short texts, research in Short Text Topic Modeling (STTM) has recently gained a lot of interest to reveal unique and cohesive latent topics. This article examines the current state of the art in STTM algorithms. It presents a comprehensive survey and taxonomy of STTM algorithms for short text topic modelling. The article also includes a qualitative and quantitative study of the STTM algorithms, as well as analyses of the various strengths and drawbacks of STTM techniques. Moreover, a comparative analysis of the topic quality and performance of representative STTM models is presented. The performance evaluation is conducted on two real-world Twitter datasets: the Real-World Pandemic Twitter (RW-Pand-Twitter) dataset and Real-world Cyberbullying Twitter (RW-CB-Twitter) dataset in terms of several metrics such as topic coherence, purity, NMI, and accuracy. Finally, the open challenges and future research directions in this promising field are discussed to highlight the trends of research in STTM. The work presented in this paper is useful for researchers interested in learning state-of-the-art short text topic modelling and researchers focusing on developing new algorithms for short text topic modelling.

Rhythmic auditory stimulation during gait adaptation enhances learning after-effects and savings by reducing common neural drives to lower limb muscles

Rhythmic auditory stimulation (RAS) improves gait symmetry in neurological patients with asymmetric gait patterns. However, whether RAS can accelerate gait adaptation remains unclear. This study aimed to investigate whether RAS during gait adaptation can enhance learning after-effects and savings of gait symmetries. Furthermore, we investigated the differences in coherence of paired surface electromyographic (EMG) recordings during gait adaptation between with and without RAS. Nineteen healthy young adults were subjected to continuous treadmill gait with swing phase perturbation (adaptation period) with or without RAS (RAS or no-RAS condition) for 5 or 10 min (short- or long-time condition), without the perturbation for 5 min (de-adaptation period), and with the perturbation for another 5 min (re-adaptation period). Swing phase and step length symmetries were significantly greater in the RAS conditions than in the no-RAS conditions during the adaptation period. Learning after-effects and savings of gait symmetries were significantly greater in the RAS conditions than in the no-RAS conditions in the early de-adaptation and re-adaptation periods, respectively. There were no significant differences in savings in the early re-adaptation period between the short- and long-time conditions in the RAS condition. EMG-EMG coherence in the rectus femoris muscle in the beta band (15-35 Hz) on the perturbed side was significantly lower during the early adaptation period in the RAS than in the no-RAS conditions. Therefore, RAS may enhance learning efficiency by reducing common neural drives from cortical structure during gait adaptation, which could induce high savings of a learned gait pattern, even within short-time periods.

Causal Evidence for a Role of Cerebellar Lobulus Simplex in Prefrontal-Hippocampal Interaction in Spatial Working Memory Decision-Making

Spatial working memory (SWM) is a cerebrocerebellar cognitive skill supporting survival-relevant behaviors, such as optimizing foraging behavior by remembering recent routes and visited sites. It is known that SWM decision-making in rodents requires the medial prefrontal cortex (mPFC) and dorsal hippocampus. The decision process in SWM tasks carries a specific electrophysiological signature of a brief, decision-related increase in neuronal communication in the form of an increase in the coherence of neuronal theta oscillations (4-12 Hz) between the mPFC and dorsal hippocampus, a finding we replicated here during spontaneous exploration of a plus maze in freely moving mice. We further evaluated SWM decision-related coherence changes within frequency bands above theta. Decision-related coherence increases occurred in seven frequency bands between 4 and 200 Hz and decision-outcome-related differences in coherence modulation occurred within the beta and gamma frequency bands and in higher frequency oscillations up to 130 Hz. With recent evidence that Purkinje cells in the cerebellar lobulus simplex (LS) represent information about the phase and phase differences of gamma oscillations in the mPFC and dorsal hippocampus, we hypothesized that LS might be involved in the modulation of mPFC-hippocampal gamma coherence. We show that optical stimulation of LS significantly impairs SWM performance and decision-related mPFC-dCA1 coherence modulation, providing causal evidence for an involvement of cerebellar LS in SWM decision-making at the behavioral and neuronal level. Our findings suggest that the cerebellum might contribute to SWM decision-making by optimizing the decision-related modulation of mPFC-dCA1 coherence.

Dilemmas and deliberations in managing the care trajectory of elderly patients with complex health needs: a single-case study

Background

Today, the ageing population is larger than ever before, and people who are living longer with chronic illnesses and multimorbidity need support from multiple healthcare service levels. Similarly, healthcare systems are becoming increasingly specialised and fragmented. The World Health Organization has highlighted novel policies for developing integrated and person-centred services. However, patients, next of kin and health professionals face several challenges in managing healthcare during the care trajectory. Limited literature has addressed the challenges experienced by these groups. Therefore, this study aimed to identify the dilemmas and deliberations faced by patients, next of kin and health professionals during the care trajectory of elderly patients with complex healthcare needs.

Method

The study had a qualitative single-case design. The case was taken from a multi-case study exploring the care trajectory of elderly patients. The participants were the patient, their next of kin and the health professionals involved in the patient’s care trajectory. Data were obtained via observation and individual interviews conducted during the patient’s hospital stay and after the patient returned home.

Results

The dilemmas and deliberations in managing the care trajectory were divided into four main themes: the health professionals’ pursuit of appropriate and feasible healthcare services, the next of kin’s planning horizons, being the person left in limbo and reorganising the home for comprehensive healthcare.

Conclusion

The pursuit of a tailored and suitable healthcare service lead to a comprehensive mobilisation of and work by all actors involved. Having a comprehensive understanding of these conditions are of importance in developing an appropriate care trajectory for the elderly patient with complex need.

Spatial Coherence Manipulation on the Disorder-Engineered Statistical Photonic Platform

Coherence, similar to amplitude, polarization, and phase, is a fundamental characteristic of the light fields and is dominated by the statistical optical property. Although spatial coherence is one of the pivotal optical dimensions, it has not been significantly manipulated on the photonic platform. Here, we theoretically and experimentally manipulate the spatial coherence of light fields by loading different random phase distributions onto the wavefront with a metasurface. We achieve the generation of partially coherent light with a predefined degree of coherence and continuously modulate it from coherent to incoherent by controlling the phase fluctuation ranges or the beam sizes. This design strategy can be easily extended to manipulate arbitrary phase-only special beams with the same degree of coherence. Our approach provides straightforward rules to manipulate the coherence of light fields in an extra-cavity-based manner and paves the way for further applications in ghost imaging and information transmission in turbulent media.

Seasonal Succession and Coherence Among Bacteria and Microeukaryotes in Lake Baikal

Microorganisms exhibit seasonal succession governed by physicochemical factors and interspecies interactions, yet drivers of this process in different environments remain to be determined. We used high-throughput sequencing of 16S rRNA and 18S rRNA genes to study seasonal dynamics of bacterial and microeukaryotic communities at pelagic site of Lake Baikal from spring (under-ice, mixing) to autumn (direct stratification). The microbial community was subdivided into distinctive coherent clusters of operational taxonomic units (OTUs). Individual OTUs were consistently replaced during different seasonal events. The coherent clusters change their contribution to the microbial community depending on season. Changes of temperature, concentrations of silicon, and nitrates are the key factors affected the structure of microbial communities. Functional prediction revealed that some bacterial or eukaryotic taxa that switched with seasons had similar functional properties, which demonstrate their functional redundancy. We have also detected specific functional properties in different coherent clusters of bacteria or microeukaryotes, which can indicate their ability to adapt to seasonal changes of environment. Our results revealed a relationship between seasonal succession, coherency, and functional features of freshwater bacteria and microeukaryotes.

Cross-validated Adaboost Classification of Emotion Regulation Strategies Identified by Spectral Coherence in Resting-State

In the present study, quantitative relations between Cognitive Emotion Regulation strategies (CERs) and EEG synchronization levels have been investigated for the first time. For this purpose, spectral coherence (COH), phase locking value and mutual information have been applied to short segments of 62-channel resting state eyes-opened EEG data collected from healthy adults who use contrasting emotion regulation strategies (frequently and rarely use of rumination&distraction, frequently and rarely use of suppression&reappraisal). In tests, the individuals are grouped depending on their self-responses to both emotion regulation questionnaire (ERQ) and cognitive ERQ. Experimental data are downloaded from publicly available data-base, LEMON. Regarding EEG electrode pairs that placed on right and left cortical regions, inter-hemispheric dependency measures are computed for non-overlapped short segments of 2 sec at 2 min duration trials. In addition to full-band EEG analysis, dependency metrics are also obtained for both alpha and beta sub-bands. The contrasting groups are discriminated from each other with respect to the corresponding features using cross-validated adaboost classifiers. High classification accuracies (CA) of 99.44% and 98.33% have been obtained through instant classification driven by full-band COH estimations. Considering regional features that provide the high CA, CERs are found to be highly relevant with associative memory functions and cognition. The new findings may indicate the close relation between neuroplasticity and cognitive skills.

Achieving greater policy coherence and harmonisation for marine litter management in the North-East Atlantic and Wider Caribbean Region

The effects of marine litter pose ecological, economic and optional value threats to the countries and territories on the margins of the Atlantic Basin. As the abundance of transboundary marine litter increases, this in turn has triggered the development of marine litter policy action plans and inter-regional collaboration. The OSPAR Commission and Cartagena Convention of North-East Atlantic (NEA) and the Wider Caribbean Region (WCR) respectively, have established a memorandum of understanding to facilitate collaboration for enhanced marine litter management. In light of this development, this paper conducts a scoping review of management measures of marine litter within these regions as well as a coherence analysis between their regional action plans (RAPs). The analysis uses a proactive framework based on a modified categorization by Chen (2015) and Williams and Rangel-Buitrago (2019) for comparatively analyse management measures. The analytical categorizations include legislation and enforcement measures, prevention, removal, monitoring, research, information management and exchange and education and outreach. Although specific approaches differed among the regions depending upon geographical and individual situations, each categorization included detailed management activities except for prevention in NEA and removal in the WCR. The comparative analysis demonstrates that there are opportunities for inter-regional cooperation, knowledge sharing and overall enhanced and informed marine litter management.

Minimum variance beamforming combined with covariance matrix-based adaptive weighting for medical ultrasound imaging

BACKGROUND

The minimum variance (MV) beamformer can significantly improve the image resolution in ultrasound imaging, but it has limited performance in noise reduction. We recently proposed the covariance matrix-based statistical beamforming (CMSB) for medical ultrasound imaging to reduce sidelobes and incoherent clutter.

METHODS

In this paper, we aim to improve the imaging performance of the MV beamformer by introducing a new pixel-based adaptive weighting approach based on CMSB, which is named as covariance matrix-based adaptive weighting (CMSAW). The proposed CMSAW estimates the mean-to-standard-deviation ratio (MSR) of a modified covariance matrix reconstructed by adaptive spatial smoothing, rotary averaging, and diagonal reducing. Moreover, adaptive diagonal reducing based on the aperture coherence is introduced in CMSAW to enhance the performance in speckle preservation.

RESULTS

The proposed CMSAW-weighted MV (CMSAW-MV) was validated through simulation, phantom experiments, and in vivo studies. The phantom experimental results show that CMSAW-MV obtains resolution improvement of 21.3% and simultaneously achieves average improvements of 96.4% and 71.8% in average contrast and generalized contrast-to-noise ratio (gCNR) for anechoic cyst, respectively, compared with MV. in vivo studies indicate that CMSAW-MV improves the noise reduction performance of MV beamformer.

CONCLUSION

Simulation, experimental, and in vivo results all show that CMSAW-MV can improve resolution and suppress sidelobes and incoherent clutter and noise. These results demonstrate the effectiveness of CMSAW in improving the imaging performance of MV beamformer. Moreover, the proposed CMSAW with a computational complexity of [Formula: see text] has the potential to be implemented in real time using the graphics processing unit.

Coronary artery perforation after bioresorbable scaffold implantation treated with a new generation covered stent-OCT insights

Background

Coronary artery perforation is a rare but potentially lethal complication of percutaneous coronary intervention (PCI) with an associated mortality of 7–17%. We report the case of coronary artery perforation complicating Absorb bioresorbable vascular scaffold (BVS) implantation and the associated technical challenges with managing this life-threatening complication.

Case report

A 46-year-old male was referred to our institution and underwent PCI with an Absorb bioabsorbable vascular scaffold (BVS) to a proximal LAD long segment bifurcation lesion. Following pre-dilation and deployment of the 3.5 × 28 mm Absorb BVS, high pressure post-dilation of the distal scaffold was complicated by a large, Ellis type III coronary perforation with no flow to the distal LAD beyond the rupture, and associated with a large pericardial effusion confirmed on bedside transthoracic echocardiogram (TTE). The insult was temporised with prolonged balloon inflation within the Absorb BVS immediately proximal to the site of perforation, permitting urgent insertion of a pericardial drain. After deflation of the balloon, a 3.0 × 21 mm BeGraft covered stent was deployed across the perforation, restoring normal LAD flow and abolishing the perforation. Cardio-pulmonary resuscitation was not required and the patient remained conscious throughout the procedure. TTE demonstrated normal left ventricular function and the patient was discharged 3 days later. Repeat angiography at 3 months showed patent stents with TIMI III flow, and optical coherence tomography (OCT) showed good expansion and apposition of the proximal Absorb BVS and BeGraft. The patient has remained well 4 years after PCI with no major cardiovascular events.

Conclusion

The utility of bioresorbable scaffold technology remains controversial although meticulous implantation techniques are associated with improved clinical outcomes. Adoption of the Pre-dilatation, Sizing and Post-dilatation (‘PSP’) method of BVS implantation with routine aggressive vessel preparation and scaffold optimization however may contribute to a higher risk of vessel perforation. The case emphasises the importance of accurate sizing of the vessel with intracoronary imaging and demonstrates the value of newer generation covered stents with single-layer design and slimmer crossing profile producing improved deliverability and procedural success.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02501-3.

Photophysics of nanographenes: from polycyclic aromatic hydrocarbons to graphene nanoribbons

Graphene quantum dots (GQDs) and nanoribbons (GNRs) are classes of nanographene molecules that exhibit highly tunable photophysical properties. There have been great strides in recent years to advance our understanding of nanographene photophysics and develop their use in light-harvesting systems, such as artificial photosynthesis. Here, we review the latest studies of GQDs and GNRs which have shed new light onto their photophysical underpinnings through computational and advanced spectroscopic techniques. We discuss how the size, symmetry, and shape of nanographenes influence their molecular orbital structures and, consequentially, their spectroscopic signatures. The scope of this review is to comprehensively lay out the general photophysics of nanographenes starting with benzene and building up to larger polycyclic aromatic hydrocarbons, GQDs, and GNRs. We also explore a collection of publications from recent years that build upon the current understanding of nanographene photophysics and their potential application in light-driven processes from display, lasing, and sensing technology to photocatalytic water splitting.

Right Anterior Theta Hypersynchrony as a Quantitative Measure Associated with Autistic Traits and K-Cl Cotransporter KCC2 Polymorphism

Our aim was to use theta coherence as a quantitative trait to investigate the relation of the polymorphisms in NKCC1 (rs3087889) and KCC2 (rs9074) channel protein genes to autistic traits (AQ) in neurotypicals. Coherence values for candidate connection regions were calculated from eyes-closed resting EEGs in two independent groups. Hypersynchrony within the right anterior region was related to AQ in both groups (p < 0.05), and variability in this hypersynchrony was related to the rs9074 polymorphism in the total group (p < 0.05). In conclusion, theta hypersynchrony within the right anterior region during eyes-closed rest can be considered a quantitative measure for autistic traits. Replicating our findings in two independent populations with different backgrounds strengthens the validity of the current study.