Interval groups related to finite Coxeter groups I

We elaborate presentations of the interval groups related to all quasi-Coxeter elements in the Coxeter group of type $D_n$. This is the only case of the infinite families of finite Coxeter groups that admits proper quasi-Coxeter elements. The presentations we obtain are over a set of generators in bijection with what we call Carter generating set, and the relations are those defined by the related Carter diagram along with a twisted or a cycle commutator relator, depending on whether the quasi-Coxeter element is a Coxeter element or not. In a subsequent work, we complete our analysis to cover all the exceptional cases of finite Coxeter groups, and establish that almost all the interval groups related to proper quasi-Coxeter elements are not isomorphic to the related Artin groups, hence establishing a new family of interval groups with nice presentations. Alongside the proof of the main results of this paper, we establish important properties related to the dual approach to Coxeter and Artin groups

Interval groups related to finite Coxeter groups, Part II

We provide a complete description of the presentations of the interval groups related to quasi-Coxeter elements in finite Coxeter groups. In the simply laced cases, we show that each interval group is the quotient of the Artin group associated with the corresponding Carter diagram by the normal closure of a set of twisted cycle commutators, one for each 4-cycle of the diagram. Our techniques also reprove an analogous result for the Artin groups of finite Coxeter groups, which are interval groups corresponding to Coxeter elements. We also analyse the situation in the non-simply laced cases, where a new Garside structure is discovered. Furthermore, we obtain a complete classification of whether the interval group we consider is isomorphic or not to the related Artin group. Indeed, using methods of Tits, we prove that the interval groups of proper quasi-Coxeter elements are not isomorphic to the Artin groups of the same type, in the case of $D_n$ when $n$ is even or in any of the exceptional cases. In [BHNR22], we show using different methods that this result holds for type $D_n$ for all $n \geq 4$

Changes in sexuality: how sexuality changes across time, across relationships, and across sociocultural contexts

This paper reviews several mid-level theories of sexuality on the theme of changes in sexuality, which is supported by evidence that changes in sexuality occur throughout time, during the course of relationships, and depending on the larger sociocultural context. The first section covers the theory of female erotic plasticity, which suggests that women on average exhibit greater variation in their sexual attitudes, desires, and behavior over the course of their lives than men. The second section addresses changes in passion over the course of romantic relationships. Changes in intimacy within a relationship over time are hypothesized to produce temporary spikes in passion and sexual behavior. The final section reviews the theory of sexual economics, which analyzes sexual behavior according to economic principles. This theory proposes that sex is a female resource that women exchange with men for other valued rewards. Changes in the sexual marketplace affect the negotiation of sex between the genders. Although these changes in sexuality are well-documented, neuroscience research is needed to shed light on how the brain enables, responds, and adjusts to these changes

Exploring real-time functional magnetic resonance imaging neurofeedback in adolescents with disruptive behavior disorder and callous unemotional traits

Introduction: Adolescents with increased callous unemotional traits (CU traits) in the context of disruptive behavior disorder (DBD) show a persistent pattern of antisocial behavior with shallow affect and a lack of empathy or remorse. The amygdala and insula as regions commonly associated with emotion processing, empathy and arousal are implicated in DBD with high CU traits. While behavioral therapies for DBD provide significant but small effects, individualized treatments targeting the implicated brain regions are missing. Methods: In this explorative randomized controlled trial we randomly assigned twenty-seven adolescents with DBD to individualized real-time functional magnetic resonance neurofeedback (rtfMRI-NF) or behavioral treatment as usual (TAU). Visual feedback of either amygdala or insula activity was provided during rtfMRI-NF by gauges and included a simple and concurrent video run plus a transfer run. A linear mixed model (LMM) was applied to determine improvement of self-regulation. Specificity was assessed by correlating individual self-regulation improvement with clinical outcomes. Results: The rtfMRI-NF (n = 11) and TAU (n = 10) completers showed comparable and significant clinical improvement indicating neither superiority nor inferiority of rtfMRI-NF. The exploratory LMM revealed successful learning of self-regulation along the course of training for participants who received feedback from the amygdala. A significant exploratory correlation between individual target region activity in the simple run and clinical improvement was found for one dimension of DBD. Conclusions: This exploratory study demonstrated feasibility and suggests clinical efficacy of individualized rtfMRI-NF comparable to active TAU for adolescents with DBD and increased CU traits. Further studies are needed to confirm efficacy, specificity and to clarify underlying learning mechanisms

Proposal for Quantum Simulation via All-Optically Generated Tensor Network States

We devise an all-optical scheme for the generation of entangled multimode photonic states encoded in temporal modes of light. The scheme employs a nonlinear down-conversion process in an optical loop to generate one- and higher-dimensional tensor network states of light. We illustrate the principle with the generation of two different classes of entangled tensor network states and report on a variational algorithm to simulate the ground-state physics of many-body systems. We demonstrate that state-of-the-art optical devices are capable of determining the ground-state properties of the spin-1/2 Heisenberg model. Finally, implementations of the scheme are demonstrated to be robust against realistic losses and mode mismatch.Comment: 6 pages main text plus 6 pages Supplementary Material and many figures. Updated to published version. Comments welcom

Predictors of Dropout in a Digital Intervention for the Prevention and Treatment of Depression in Patients With Chronic Back Pain : Secondary Analysis of Two Randomized Controlled Trials

Peer reviewe

Amygdala-related electrical fingerprint is modulated with neurofeedback training and correlates with deep-brain activation: proof-of-concept in borderline personality disorder

Background: The modulation of brain circuits of emotion is a promising pathway to treat borderline personality disorder (BPD). Precise and scalable approaches have yet to be established. Two studies investigating the amygdala-related electrical fingerprint (Amyg-EFP) in BPD are presented: one study addressing the deep-brain correlates of Amyg-EFP, and a second study investigating neurofeedback (NF) as a means to improve brain self-regulation. Methods: Study 1 combined electroencephalography (EEG) and simultaneous functional magnetic resonance imaging to investigate the replicability of Amyg-EFP-related brain activation found in the reference dataset (N = 24 healthy subjects, 8 female; re-analysis of published data) in the replication dataset (N = 16 female individuals with BPD). In the replication dataset, we additionally explored how the Amyg-EFP would map to neural circuits defined by the research domain criteria. Study 2 investigated a 10-session Amyg-EFP NF training in parallel to a 12-weeks residential dialectical behavior therapy (DBT) program. Fifteen patients with BPD completed the training, N = 15 matched patients served as DBT-only controls. Results: Study 1 replicated previous findings and showed significant amygdala blood oxygenation level dependent activation in a whole-brain regression analysis with the Amyg-EFP. Neurocircuitry activation (negative affect, salience, and cognitive control) was correlated with the Amyg-EFP signal. Study 2 showed Amyg-EFP modulation with NF training, but patients received reversed feedback for technical reasons, which limited interpretation of results. Conclusions: Recorded via scalp EEG, the Amyg-EFP picks up brain activation of high relevance for emotion. Administering Amyg-EFP NF in addition to standardized BPD treatment was shown to be feasible. Clinical utility remains to be investigated

Randomized Controlled Trial of Individualized Arousal-Biofeedback for children and adolescents with Disruptive Behavior Disorders (DBD)

Background: Disruptive behavior disorders (including conduct disorder (CD) and oppositional defiant disorder (ODD)) are common childhood and adolescent psychiatric conditions often linked to altered arousal. The recommended first-line treatment is multi-modal therapy and includes psychosocial and behavioral interventions. Their modest effect sizes along with clinically and biologically heterogeneous phenotypes, emphasize the need for innovative personalized treatment targeting impaired functions such as arousal dysregulation. Methods: A total of 37 children aged 8-14 years diagnosed with ODD/CD were randomized to 20 sessions of individualized arousal biofeedback using skin conductance levels (SCL-BF) or active treatment as usual (TAU) including psychoeducation and cognitive-behavioral elements. The primary outcome was the change in parents´ ratings of aggressive behavior measured by the Modified Overt Aggression Scale. Secondary outcome measures were subscales from the Child Behavior Checklist, the Inventory of Callous-Unemotional traits and the Reactive-Proactive Aggression Questionnaire. Results: The SCL-BF treatment was neither superior nor inferior to the active TAU. Both groups showed reduced aggression after treatment with small effects for the primary outcome and large effects for some secondary outcomes. Importantly, successful learning of SCL self-regulation was related to reduced aggression at post-assessment. Conclusions: Individualized SCL-BF was not inferior to active TAU for any treatment outcome with improvements in aggression. Further, participants were on average able to self-regulate their SCL, and those who best learned self-regulation showed the highest clinical improvement, pointing to specificity of SCL-BF regulation for improving aggression. Further studies with larger samples and improved methods, for example by developing BF for mobile use in ecologically more valid settings are warranted

Cadmium Telluride Quantum Dots as a Fluorescence Marker for Adipose Tissue Grafts

Plastic and reconstructive surgeons increasingly apply adipose tissue grafting in a clinical setting, although the anticipation of graft survival is insecure. There are only few tools for tracking transplanted fat grafts in vivo. Murine adipose tissue clusters were incubated with negatively charged, mercaptoproprionic acid-coated cadmium telluride quantumdots (QDs) emitting in the dark red or near infrared. The intracellular localization of QDs was studied by confocal laser scanning microscopy. As a result, the adipose tissue clusters showed a proportional increase in fluorescence with increasing concentrations (1, 10, 16, 30, 50 nM) of cadmium telluride QDs. Laser scanning microscopy demonstrated a membrane bound localization of QDs. Vacuoles and cell nuclei of adipocytes were spared by QDs. We conclude that QDs were for the first time proven intracellular in adult adipocytes and demonstrate a strong fluorescence signal. Therefore, they may play an essential role for in vivo tracking of fat grafts