Uncertainty about potential future threats and the associated anxious anticipation represents a key feature of anxiety. However, the neural systems that underlie the subjective experience of threat ...anticipation under uncertainty remain unclear. Combining an uncertainty-variation threat anticipation paradigm that allows precise modulation of the level of momentary anxious arousal during functional magnetic resonance imaging (fMRI) with multivariate predictive modeling, we train a brain model that accurately predicts subjective anxious arousal intensity during anticipation and test it across 9 samples (total n = 572, both gender). Using publicly available datasets, we demonstrate that the whole-brain signature specifically predicts anxious anticipation and is not sensitive in predicting pain, general anticipation or unspecific emotional and autonomic arousal. The signature is also functionally and spatially distinguishable from representations of subjective fear or negative affect. We develop a sensitive, generalizable, and specific neuroimaging marker for the subjective experience of uncertain threat anticipation that can facilitate model development.
We present here an adaptive control scheme with a feedback delay to achieve elimination of synchronization in a large population of coupled and synchronized oscillators. We validate the feasibility ...of this scheme not only in the coupled Kuramoto's oscillators with a unimodal or bimodal distribution of natural frequency, but also in two representative models of neuronal networks, namely, the FitzHugh-Nagumo spiking oscillators and the Hindmarsh-Rose bursting oscillators. More significantly, we analytically illustrate the feasibility of the proposed scheme with a feedback delay and reveal how the exact topological form of the bimodal natural frequency distribution influences the scheme performance. We anticipate that our developed scheme will deepen the understanding and refinement of those controllers, e.g. techniques of deep brain stimulation, which have been implemented in remedying some synchronization-induced mental disorders including Parkinson disease and epilepsy.
Marine phytoplankton play a central role in supporting life in the oceans and profoundly affect global biogeochemical cycles. Previous studies have revealed positive effects of sea‐surface ...temperature (SST) on phytoplankton in terms of chlorophyll a concentrations (Chla) in high latitude oceans, while negative effects prevail in tropical and midlatitude oceans as well as under stratified summer conditions at higher latitudes. Based on a global analysis of 20 years of ocean Chla and SST data, we first investigated how interannual variability in SST is associated with Chla for each month of the season for every ocean province. We then quantified how the SST‐Chla relationships varied with the long‐term average (baseline) SST. We found significant season‐dependent SST effects on Chla in most ocean provinces. The signs and magnitudes of these effects were consistently associated with the baseline SST, with a shift from positive to negative effects of SST on Chla around 14°C. Based on field observations and literature data, we also estimated the interaction between nitrate limitation and temperature on the SST‐Chla relationship. Our findings suggest that the ocean warming effects on Chla depend consistently on the baseline temperature, both with regard to seasonal effects within regions and regional effects between high and low latitude provinces. Our analysis further suggests that the monthly 14°C isotherms can be used as a first approximation to separate areas and seasons where warming has opposite signed effects.
Key Points
Nonlinear temperature effect on global ocean chlorophyll a was found
Chlorophyll a increased with increasing temperatures up to around 14°C
Chlorophyll a decreased with increasing temperatures above 14°C
To investigate the relation between parental age, and behavioral, cognitive and brain differences in the children.
Data with children aged 9-11 of 8709 mothers with parental age 15-45 years were ...analyzed from the Adolescent Brain Cognitive Development (ABCD) study. A general linear model was used to test the associations of the parental age with brain structure, and behavioral and cognitive problems scores.
Behavioral and cognitive problems were greater in the children of the younger mothers, and were associated with lower volumes of cortical regions in the children. There was a linear correlation between the behavioral and cognitive problems scores, and the lower brain volumes (r > 0.6), which was evident when parental age was included as a stratification factor. The regions with lower volume included the anterior cingulate cortex, medial and lateral orbitofrontal cortex and amygdala, parahippocampal gyrus and hippocampus, and temporal lobe (FDR corrected p < 0.01). The lower cortical volumes and areas in the children significantly mediated the association between the parental age and the behavioral and cognitive problems in the children (all p < 10
). The effects were large, such as the 71.4% higher depressive problems score, and 27.5% higher rule-breaking score, in the children of mothers aged 15-19 than the mothers aged 34-35.
Lower parental age is associated with behavioral problems and reduced cognitive performance in the children, and these differences are related to lower volumes and areas of some cortical regions which mediate the effects in the children. The findings are relevant to psychiatric understanding and assessment.
In this paper, we focus on the asymptotic and transient dynamics of the studied ecosystem and measure the response to perturbation of the stochastic ratio-dependent predator–prey model. The method we ...use is mainly based on the Kronecker product and numerical simulation. Firstly, the mean-square stability matrix can be calculated from the Kronecker product, so as to compute three indicators (root-mean-square resilience, root-mean-square reactivity and root-mean-square amplification envelope) of the response to perturbation for the studied ecosystem. Since the above-measured amounts cannot be obtained explicitly, we use numerical simulation to draw the changing figures within the appropriate parameter range. Then we obtain some conclusions by comparing the numerical results. When perturbing any populations, increasing the disturbance intensity will reduce the mean-square stable area of the system. Ecologists can manage the ecosystem, reduce losses and maximize benefits according to the numerical results of the root-mean-square amplification envelope.
Glioma is the most frequent form of malignant brain tumors. Surgical debulking is a major strategy for glioma treatment. However, there is a great challenge for the neurosurgeons to intraoperatively ...identify the true margins of glioma because of its infiltrative nature. Tumor residues or microscopic satellite foci left in the resection bed are the main reasons leading to early recurrence as well as poor prognosis. In this study, a surface-enhanced resonance Raman scattering (SERRS) probe was developed to intraoperatively guide glioma resection. In this probe, molecular reporters with absorptive maxima at the near-infrared wavelength range were covalently functionalized on the surface of gold nanostars. This SERRS probe demonstrated an ultrahigh sensitivity with a detection limit of 5.0 pM in aqueous solution. By the development of glioma xenografts in a mouse dorsal skin window chamber, extravasation of this probe from leaky tumor vasculature as functions of time and distance to tumor boundary was investigated. Importantly, the invasive margin of the tumor xenograft was demarcated by this probe with a high signal-to-background ratio. Preoperative magnetic resonance imaging (MRI) first defined the position of orthotopic glioma xenografts in the brain of rat models, and the craniotomy plan was designed. The brain tumor was then excised intraoperatively step-by-step with the assistance of a handheld Raman scanner till the Raman signals of the probe completely disappeared in the resection bed. Notably, longitudinal MRI showed that SERRS-guided surgery significantly reduced the tumor recurrence rate and improved the overall survival of rat models compared with the white light-guided surgery. Overall, this work demonstrates the prognostic benefit of SERRS-guided glioma surgery in animal models. Because delineation of tumor-invasive margins is a common challenge faced by the surgeons, this SERRS probe with a picomolar detection limit holds the promise in improving the surgical outcome of different types of infiltrated tumors.
Two studies have suggested that severe prolonged nausea and vomiting during pregnancy is associated with emotional and behavioral problems in offspring, with smaller sample size and short-term ...follow-up. Moreover, little information is available on the role of the brain structure in the associations.
In a US-based cohort, the association was investigated between severe prolonged nausea and vomiting in pregnancy (extending after the second trimester and termed SNVP), psychiatric and cognitive problems, and brain morphology, from the Adolescent Brain Cognitive Development (ABCD) study, from 10,710 children aged 9-11 years. We validated the emotional including psychiatric findings using the Danish National Cohort Study with 2,092,897 participants.
SNVP was significantly associated with emotional and psychiatric problems (t = 8.89, Cohen's d = 0.172, p = 6.9 × 10
) and reduced global cognitive performance (t = - 4.34, d = - 0.085, p = 1.4 × 10
) in children. SNVP was associated with low cortical area and volume, especially in the cingulate cortex, precuneus, and superior medial prefrontal cortex. These lower cortical areas and volumes significantly mediated the relation between SNVP and the psychiatric and cognitive problems in children. In the Danish National Cohort, severe nausea and vomiting in pregnancy were significantly associated with increased risks of behavioral and emotional disorders in children (hazard ratio, 1.24; 95% confidence interval, 1.16-1.33).
SNVP is strongly associated with psychiatric and cognitive problems in children, with mediation by brain structure. These associations highlight the clinical importance and potential benefits of the treatment of SNVP, which could reduce the risk of psychiatric disorder in the next generation.
Recent experimental observations have supported the hypothesis that the cerebral cortex operates in a dynamical regime near criticality, where the neuronal network exhibits a mixture of ordered and ...disordered patterns. However, A comprehensive study of how criticality emerges and how to reproduce it is still lacking. In this study, we investigate coupled networks with conductance-based neurons and illustrate the co-existence of different spiking patterns, including asynchronous irregular (AI) firing and synchronous regular (SR) state, along with a scale-invariant neuronal avalanche phenomenon (criticality). We show that fast-acting synaptic coupling can evoke neuronal avalanches in the mean-dominated regime but has little effect in the fluctuation-dominated regime. In a narrow region of parameter space, the network exhibits avalanche dynamics with power-law avalanche size and duration distributions. We conclude that three stages which may be responsible for reproducing the synchronized bursting: mean-dominated subthreshold dynamics, fast-initiating a spike event, and time-delayed inhibitory cancellation. Remarkably, we illustrate the mechanisms underlying critical avalanches in the presence of noise, which can be explained as a stochastic crossing state around the Hopf bifurcation under the mean-dominated regime. Moreover, we apply the ensemble Kalman filter to determine and track effective connections for the neuronal network. The method is validated on noisy synthetic BOLD signals and could exactly reproduce the corresponding critical network activity. Our results provide a special perspective to understand and model the criticality, which can be useful for large-scale modeling and computation of brain dynamics.
For most people, adolescence is synonymous with emotional turmoil and it has been shown that early difficulties with emotion regulation can lead to persistent problems for some people. This suggests ...that intervention during development might reduce long-term negative consequences for those individuals. Recent research has highlighted the suitability of real-time fMRI-based neurofeedback (NF) in training emotion regulation (ER) networks in adults. However, its usefulness in directly influencing plasticity in the maturing ER networks remains unclear. Here, we used NF to teach a group of 17 7–16 year-olds to up-regulate the bilateral insula, a key ER region. We found that all participants learned to increase activation during the up-regulation trials in comparison to the down-regulation trials. Importantly, a subsequent Granger causality analysis of Granger information flow within the wider ER network found that during up-regulation trials, bottom-up driven Granger information flow increased from the amygdala to the bilateral insula and from the left insula to the mid-cingulate cortex, supplementary motor area and the inferior parietal lobe. This was reversed during the down-regulation trials, where we observed an increase in top-down driven Granger information flow to the bilateral insula from mid-cingulate cortex, pre-central gyrus and inferior parietal lobule. This suggests that: 1) NF training had a differential effect on up-regulation vs down-regulation network connections, and that 2) our training was not only superficially concentrated on surface effects but also relevant with regards to the underlying neurocognitive bases. Together these findings highlight the feasibility of using NF in children and adolescents and its possible use for shaping key social cognitive networks during development.
•Brain-based emotion regulation networks develop continuously throughout adolescence.•These networks can strengthen in response to fMRI neurofeedback (NF).•Here we used NF to increase insula response in a group of 7–17 year-olds.•Our NF training also had a strengthening effect on the emotion regulation network.•Future research could begin to explore the use of NF for facilitating clinical change.
Organisms are increasingly tolerant to metal toxicity in the natural ecosystems, which did not match the results of the environmental risk assessment (ERA) of metals based on toxicity data from ...organisms in the laboratory. Studies have described the effects of pre-exposure to metals on metal toxicity tolerance in terms of the toxicokinetic (TK) process; however, the toxicodynamic (TD) process may be more susceptible to metal pre-exposure. Therefore, to determine whether pre-exposure to low concentrations of silver (Ag) or cadmium (Cd) affects the metal TK and TD processes of zebrafish (Danio rerio) larvae, we investigated four TK–TD model parameters that control tolerance and sensitivity to metal toxicity on the survival. Our results showed that the killing rate (ks) of larvae exposed to high Cd concentrations was significantly lower following pre-exposure to 10 μg/L Cd than that of larvaenot pre-exposed. However, the ks for high Ag concentrations was significantly higher in zebrafish larvae following pre-exposure to 2 μg/L Ag than in larvae not pre-exposed. In other words, a one-day pre-exposure to 2 µg/L Ag rendered the larvae more sensitive to Ag during a subsequent 4-day exposure to higher Ag concentrations, whereas a one-day pre-exposure to 10 µg/L Cd rendered the larvae more tolerance to Cd during a subsequent 4-day exposure to higher Cd concentrations. Our results further the current understanding of toxic metal tolerance mechanisms, both in TK and TD processes, and they will guide future laboratory studies to assess actual pre-exposure scenarios that occur in natural environments. Thus, our study can help reduce uncertainty in testing and improve ecological management concerning metal risk assessments.
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•Influence of Ag and Cd pre-exposure on the survival of zebrafish larvae was different.•A 1-day pre-exposure to 2 μg/L Ag renders the larvae more sensitivity to higher Ag concentrations.•A 1-day pre-exposure to 10 μg/L Cd renders the larvae more tolerant to higher Cd concentrations.•Killing rate ks in toxicodynamics model can quantify the tolerance in the survival of larvae.
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